The netfilter/iptables module in Linux before 2.6.8.1 allows remote attackers to cause a denial of service (kernel crash) or bypass firewall rules via crafted packets, which are not properly handled by the skb_checksum_help function.

The original update lacked recompiled ALSA modules against the new  kernel ABI. Furthermore, kernel-latest-2.4-sparc now correctly  depends on the updated packages. For completeness we're providing the  original problem description :

  Several local and remote vulnerabilities have been discovered in the   Linux kernel that may lead to a denial of service or the execution   of arbitrary code. The Common Vulnerabilities and Exposures project   identifies the following problems :

    - CVE-2004-0887       Martin Schwidefsky discovered that the privileged       instruction SACF (Set Address Space Control Fast) on       the S/390 platform is not handled properly, allowing       for a local user to gain root privileges.

    - CVE-2004-1058       A race condition allows for a local user to read the       environment variables of another process that is still       spawning through /proc/.../cmdline.

    - CVE-2004-2607       A numeric casting discrepancy in sdla_xfer allows       local users to read portions of kernel memory via a       large len argument which is received as an int but       cast to a short, preventing read loop from filling a       buffer.

    - CVE-2005-0449       An error in the skb_checksum_help() function from the       netfilter framework has been discovered that allows       the bypass of packet filter rules or a denial of       service attack.

    - CVE-2005-1761       A vulnerability in the ptrace subsystem of the IA-64       architecture can allow local attackers to overwrite       kernel memory and crash the kernel.

    - CVE-2005-2457       Tim Yamin discovered that insufficient input       validation in the compressed ISO file system (zisofs)       allows a denial of service attack through maliciously       crafted ISO images.

    - CVE-2005-2555       Herbert Xu discovered that the setsockopt() function       was not restricted to users/processes with the       CAP_NET_ADMIN capability. This allows attackers to       manipulate IPSEC policies or initiate a denial of       service attack.

    - CVE-2005-2709       Al Viro discovered a race condition in the /proc       handling of network devices. A (local) attacker could       exploit the stale reference after interface shutdown       to cause a denial of service or possibly execute code       in kernel mode.

    - CVE-2005-2973       Tetsuo Handa discovered that the udp_v6_get_port()       function from the IPv6 code can be forced into an       endless loop, which allows a denial of service attack.

    - CVE-2005-3257       Rudolf Polzer discovered that the kernel improperly       restricts access to the KDSKBSENT ioctl, which can       possibly lead to privilege escalation.

    - CVE-2005-3783       The ptrace code using CLONE_THREAD didn't use the       thread group ID to determine whether the caller is       attaching to itself, which allows a denial of service       attack.

    - CVE-2005-3806       Yen Zheng discovered that the IPv6 flow label code       modified an incorrect variable, which could lead to       memory corruption and denial of service.

    - CVE-2005-3848       Ollie Wild discovered a memory leak in the       icmp_push_reply() function, which allows denial of       service through memory consumption.

    - CVE-2005-3857       Chris Wright discovered that excessive allocation of       broken file lock leases in the VFS layer can exhaust       memory and fill up the system logging, which allows       denial of service.

    - CVE-2005-3858       Patrick McHardy discovered a memory leak in the       ip6_input_finish() function from the IPv6 code, which       allows denial of service.

    - CVE-2005-4618       Yi Ying discovered that sysctl does not properly       enforce the size of a buffer, which allows a denial of       service attack.

Several local and remote vulnerabilities have been discovered in the Linux kernel that may lead to a denial of service or the execution of arbitrary code. The Common Vulnerabilities and Exposures project identifies the following problems :

  - CVE-2004-1017     Multiple overflows exist in the io_edgeport driver which     might be usable as a denial of service attack vector.

  - CVE-2005-0124     Bryan Fulton reported a bounds checking bug in the     coda_pioctl function which may allow local users to     execute arbitrary code or trigger a denial of service     attack.

  - CVE-2005-0449     An error in the skb_checksum_help() function from the     netfilter framework has been discovered that allows the     bypass of packet filter rules or a denial of service     attack.

  - CVE-2005-2457     Tim Yamin discovered that insufficient input validation     in the zisofs driver for compressed ISO file systems     allows a denial of service attack through maliciously     crafted ISO images.

  - CVE-2005-2490     A buffer overflow in the sendmsg() function allows local     users to execute arbitrary code.

  - CVE-2005-2555     Herbert Xu discovered that the setsockopt() function was     not restricted to users/processes with the CAP_NET_ADMIN     capability. This allows attackers to manipulate IPSEC     policies or initiate a denial of service attack. 

  - CVE-2005-2709     Al Viro discovered a race condition in the /proc     handling of network devices. A (local) attacker could     exploit the stale reference after interface shutdown to     cause a denial of service or possibly execute code in     kernel mode.

  - CVE-2005-2800     Jan Blunck discovered that repeated failed reads of     /proc/scsi/sg/devices leak memory, which allows a denial     of service attack.

  - CVE-2005-2973     Tetsuo Handa discovered that the udp_v6_get_port()     function from the IPv6 code can be forced into an     endless loop, which allows a denial of service attack.

  - CVE-2005-3044     Vasiliy Averin discovered that the reference counters     from sockfd_put() and fput() can be forced into     overlapping, which allows a denial of service attack     through a NULL pointer dereference.

  - CVE-2005-3053     Eric Dumazet discovered that the set_mempolicy() system     call accepts a negative value for its first argument,     which triggers a BUG() assert. This allows a denial of     service attack.

  - CVE-2005-3055     Harald Welte discovered that if a process issues a USB     Request Block (URB) to a device and terminates before     the URB completes, a stale pointer would be     dereferenced. This could be used to trigger a denial of     service attack.

  - CVE-2005-3180     Pavel Roskin discovered that the driver for Orinoco     wireless cards clears its buffers insufficiently. This     could leak sensitive information into user space.

  - CVE-2005-3181     Robert Derr discovered that the audit subsystem uses an     incorrect function to free memory, which allows a denial     of service attack.

  - CVE-2005-3257     Rudolf Polzer discovered that the kernel improperly     restricts access to the KDSKBSENT ioctl, which can     possibly lead to privilege escalation.

  - CVE-2005-3356     Doug Chapman discovered that the mq_open syscall can be     tricked into decrementing an internal counter twice,     which allows a denial of service attack through a kernel     panic.

  - CVE-2005-3358     Doug Chapman discovered that passing a zero bitmask to     the set_mempolicy() system call leads to a kernel panic,     which allows a denial of service attack.

  - CVE-2005-3783     The ptrace code using CLONE_THREAD didn't use the thread     group ID to determine whether the caller is attaching to     itself, which allows a denial of service attack.

  - CVE-2005-3784     The auto-reaping of child processes functionality     included ptraced-attached processes, which allows denial     of service through dangling references.

  - CVE-2005-3806     Yen Zheng discovered that the IPv6 flow label code     modified an incorrect variable, which could lead to     memory corruption and denial of service.

  - CVE-2005-3847     It was discovered that a threaded real-time process,     which is currently dumping core can be forced into a     dead-lock situation by sending it a SIGKILL signal,     which allows a denial of service attack. 

  - CVE-2005-3848     Ollie Wild discovered a memory leak in the     icmp_push_reply() function, which allows denial of     service through memory consumption.

  - CVE-2005-3857     Chris Wright discovered that excessive allocation of     broken file lock leases in the VFS layer can exhaust     memory and fill up the system logging, which allows     denial of service.

  - CVE-2005-3858     Patrick McHardy discovered a memory leak in the     ip6_input_finish() function from the IPv6 code, which     allows denial of service.

  - CVE-2005-4605     Karl Janmar discovered that a signedness error in the     procfs code can be exploited to read kernel memory,     which may disclose sensitive information.

  - CVE-2005-4618     Yi Ying discovered that sysctl does not properly enforce     the size of a buffer, which allows a denial of service     attack.

  - CVE-2006-0095     Stefan Rompf discovered that dm_crypt does not clear an     internal struct before freeing it, which might disclose     sensitive information.

  - CVE-2006-0096     It was discovered that the SDLA driver's capability     checks were too lax for firmware upgrades.

  - CVE-2006-0482     Ludovic Courtes discovered that get_compat_timespec()     performs insufficient input sanitizing, which allows a     local denial of service attack.

  - CVE-2006-1066     It was discovered that ptrace() on the ia64 architecture     allows a local denial of service attack, when preemption     is enabled.

Updated kernel packages that fix several security issues are now available for Red Hat Enterprise Linux 4.

This update has been rated as having important security impact by the Red Hat Security Response Team.

[Updated 9 August 2005] The advisory text has been updated to show that this update fixed the security issue named CVE-2005-0210 but not CVE-2005-0209. The issue CVE-2005-0209 was actually fixed by RHSA-2005:420. No changes have been made to the packages associated with this advisory.

The Linux kernel handles the basic functions of the operating system.

A flaw in the fib_seq_start function was discovered. A local user could use this flaw to cause a denial of service (system crash) via /proc/net/route. (CVE-2005-1041)

A flaw in the tmpfs file system was discovered. A local user could use this flaw to cause a denial of service (system crash). (CVE-2005-0977)

An integer overflow flaw was found when writing to a sysfs file. A local user could use this flaw to overwrite kernel memory, causing a denial of service (system crash) or arbitrary code execution.
(CVE-2005-0867)

Keith Owens reported a flaw in the Itanium unw_unwind_to_user function. A local user could use this flaw to cause a denial of service (system crash) on Itanium architectures. (CVE-2005-0135)

A flaw in the NFS client O_DIRECT error case handling was discovered.
A local user could use this flaw to cause a denial of service (system crash). (CVE-2005-0207)

A small memory leak when defragmenting local packets was discovered that affected the Linux 2.6 kernel netfilter subsystem. A local user could send a large number of carefully crafted fragments leading to memory exhaustion (CVE-2005-0210)

A flaw was discovered in the Linux PPP driver. On systems allowing remote users to connect to a server using ppp, a remote client could cause a denial of service (system crash). (CVE-2005-0384)

A flaw was discovered in the ext2 file system code. When a new directory is created, the ext2 block written to disk is not initialized, which could lead to an information leak if a disk image is made available to unprivileged users. (CVE-2005-0400)

A flaw in fragment queuing was discovered that affected the Linux kernel netfilter subsystem. On systems configured to filter or process network packets (e.g. firewalling), a remote attacker could send a carefully crafted set of fragmented packets to a machine and cause a denial of service (system crash). In order to sucessfully exploit this flaw, the attacker would need to know or guess some aspects of the firewall ruleset on the target system. (CVE-2005-0449)

A number of flaws were found in the Linux 2.6 kernel. A local user could use these flaws to read kernel memory or cause a denial of service (crash). (CVE-2005-0529, CVE-2005-0530, CVE-2005-0531)

An integer overflow in sys_epoll_wait in eventpoll.c was discovered. A local user could use this flaw to overwrite low kernel memory. This memory is usually unused, not usually resulting in a security consequence. (CVE-2005-0736)

A flaw when freeing a pointer in load_elf_library was discovered. A local user could potentially use this flaw to cause a denial of service (crash). (CVE-2005-0749)

A flaw was discovered in the bluetooth driver system. On systems where the bluetooth modules are loaded, a local user could use this flaw to gain elevated (root) privileges. (CVE-2005-0750)

A race condition was discovered that affected the Radeon DRI driver. A local user who has DRI privileges on a Radeon graphics card may be able to use this flaw to gain root privileges. (CVE-2005-0767)

Multiple range checking flaws were discovered in the iso9660 file system handler. An attacker could create a malicious file system image which would cause a denial or service or potentially execute arbitrary code if mounted. (CVE-2005-0815)

A flaw was discovered when setting line discipline on a serial tty. A local user may be able to use this flaw to inject mouse movements or keystrokes when another user is logged in. (CVE-2005-0839)

Red Hat Enterprise Linux 4 users are advised to upgrade their kernels to the packages associated with their machine architectures and configurations as listed in this erratum.

Please note that

Updated kernel packages that fix several security issues in the Red Hat Enterprise Linux 3 kernel are now available.

This security advisory has been rated as having important security impact by the Red Hat Security Response Team.

The Linux kernel handles the basic functions of the operating system.

The following security issues were fixed :

The Vicam USB driver did not use the copy_from_user function to access userspace, crossing security boundaries. (CVE-2004-0075)

The ext3 and jfs code did not properly initialize journal descriptor blocks. A privileged local user could read portions of kernel memory.
(CVE-2004-0177)

The terminal layer did not properly lock line discipline changes or pending IO. An unprivileged local user could read portions of kernel memory, or cause a denial of service (system crash). (CVE-2004-0814)

A race condition was discovered. Local users could use this flaw to read the environment variables of another process that is still spawning via /proc/.../cmdline. (CVE-2004-1058)

A flaw in the execve() syscall handling was discovered, allowing a local user to read setuid ELF binaries that should otherwise be protected by standard permissions. (CVE-2004-1073). Red Hat originally reported this as being fixed by RHSA-2004:549, but the associated fix was missing from that update.

Keith Owens reported a flaw in the Itanium unw_unwind_to_user() function. A local user could use this flaw to cause a denial of service (system crash) on the Itanium architecture. (CVE-2005-0135)

A missing Itanium syscall table entry could allow an unprivileged local user to cause a denial of service (system crash) on the Itanium architecture. (CVE-2005-0137)

A flaw affecting the OUTS instruction on the AMD64 and Intel EM64T architectures was discovered. A local user could use this flaw to access privileged IO ports. (CVE-2005-0204)

A flaw was discovered in the Linux PPP driver. On systems allowing remote users to connect to a server using ppp, a remote client could cause a denial of service (system crash). (CVE-2005-0384)

A flaw in the Red Hat backport of NPTL to Red Hat Enterprise Linux 3 was discovered that left a pointer to a freed tty structure. A local user could potentially use this flaw to cause a denial of service (system crash) or possibly gain read or write access to ttys that should normally be prevented. (CVE-2005-0403)

A flaw in fragment queuing was discovered affecting the netfilter subsystem. On systems configured to filter or process network packets (for example those configured to do firewalling), a remote attacker could send a carefully crafted set of fragmented packets to a machine and cause a denial of service (system crash). In order to sucessfully exploit this flaw, the attacker would need to know (or guess) some aspects of the firewall ruleset in place on the target system to be able to craft the right fragmented packets. (CVE-2005-0449)

Missing validation of an epoll_wait() system call parameter could allow a local user to cause a denial of service (system crash) on the IBM S/390 and zSeries architectures. (CVE-2005-0736)

A flaw when freeing a pointer in load_elf_library was discovered. A local user could potentially use this flaw to cause a denial of service (system crash). (CVE-2005-0749)

A flaw was discovered in the bluetooth driver system. On system where the bluetooth modules are loaded, a local user could use this flaw to gain elevated (root) privileges. (CVE-2005-0750)

In addition to the security issues listed above, there was an important fix made to the handling of the msync() system call for a particular case in which the call could return without queuing modified mmap()'ed data for file system update. (BZ 147969)

Note: The kernel-unsupported package contains various drivers and modules that are unsupported and therefore might contain security problems that have not been addressed.

Red Hat Enterprise Linux 3 users are advised to upgrade their kernels to the packages associated with their machine architectures/configurations

Please note that the fix for CVE-2005-0449 required changing the external symbol linkages (kernel module ABI) for the ip_defrag() and ip_ct_gather_frags() functions. Any third-party module using either of these would also need to be fixed.

Updated kernel packages are now available as part of ongoing support and maintenance of Red Hat Enterprise Linux version 2.1. This is the seventh regular update.

This security advisory has been rated as having important security impact by the Red Hat Security Response Team.

The Linux kernel handles the basic functions of the operating system.

This is the seventh regular kernel update to Red Hat Enterprise Linux 2.1

The following security updates were made :

A flaw in fragment queuing was discovered that affected the Linux 2.4 and Linux 2.6 kernel netfilter subsystem. On systems configured to filter or process network packets (for example those configured to do firewalling), a remote attacker could send a carefully crafted set of fragmented packets to a machine and cause a denial of service (system crash). In order to sucessfully exploit this flaw, the attacker would need to know (or guess) some aspects of the firewall ruleset in place on the target system to be able to craft the right fragmented packets.
(CVE-2005-0449)

A flaw was discovered in the Linux PPP driver. On systems allowing remote users to connect to a server using ppp, a remote client could cause a denial of service (system crash). (CVE-2005-0384)

A flaw was discovered in the bluetooth driver system. On system where the bluetooth modules are loaded, a local user could use this flaw to gain elevated (root) privileges. (CVE-2005-0750)

An integer overflow flaw was discovered in the ubsec_keysetup function in the Broadcom 5820 cryptonet driver. On systems using this driver, a local user could cause a denial of service (crash) or possibly gain elevated privileges. (CVE-2004-0619) Please note that this update contains an unpatched kernel module called bcm5820_old for backwards compatibility which is still vulnerable to CVE-2004-0619.

The following device drivers have been updated to new versions :

mptfusion: 2.05.16 -> 2.05.16.02 bcm5820: 1.17 -> 1.81 cciss: 2.4.52
-> 2.4.54 qla2x00: 6.04.01 -> 7.01.01

There were many bug fixes in various parts of the kernel. The ongoing effort to resolve these problems has resulted in a marked improvement in the reliability and scalability of Red Hat Enterprise Linux 2.1.

Bug fixes include: - Fixes an incorrect and ever-changing physical_id field in /proc/cpuinfo. - Now recognizes a particular e1000 device (PCI ID 8086:1014) - Fixes a panic in disk quota code - Fixes a bug in which msync(...MS_SYNC) returns before the data is written to disk - Adds new devices to the SCSI scan list so they can be initialized and handled properly: LSI ProFibre 4000R, HP HSV200/210, HP MSA, STK OPENstorage D178. - Fixes a potential format overflow in /proc/partitions - Restores module parameters to the e100 driver for compatibility with existing customer scripts. - Fixes a bug in which cat'ing /proc/mdstat while adding/removing devices can cause a kernel oops

All Red Hat Enterprise Linux 2.1 users are advised to upgrade their kernels to the packages associated with their machine architectures and configurations as listed in this erratum.

Please note that a vulnerability addressed by this update (CVE-2005-0449) required a change to the kernel module ABI which could cause third party modules to not work. However, Red Hat is currently not aware of any module that would be affected by this change.

The remote Redhat Enterprise Linux 4 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2005:366 advisory.

    The Linux kernel handles the basic functions of the operating system.

    A flaw in the fib_seq_start function was discovered. A local user could use     this flaw to cause a denial of service (system crash) via /proc/net/route.
    (CAN-2005-1041)

    A flaw in the tmpfs file system was discovered. A local user could use this     flaw to cause a denial of service (system crash). (CAN-2005-0977)

    An integer overflow flaw was found when writing to a sysfs file. A local     user could use this flaw to overwrite kernel memory, causing a denial of     service (system crash) or arbitrary code execution. (CAN-2005-0867)

    Keith Owens reported a flaw in the Itanium unw_unwind_to_user function. A     local user could use this flaw to cause a denial of service (system crash)     on Itanium architectures. (CAN-2005-0135)

    A flaw in the NFS client O_DIRECT error case handling was discovered. A     local user could use this flaw to cause a denial of service (system crash).
    (CAN-2005-0207)

    A small memory leak when defragmenting local packets was discovered that     affected the Linux 2.6 kernel netfilter subsystem.  A local user could send     a large number of carefully crafted fragments leading to memory exhaustion     (CAN-2005-0210)

    A flaw was discovered in the Linux PPP driver. On systems allowing remote     users to connect to a server using ppp, a remote client could cause a     denial of service (system crash). (CAN-2005-0384)

    A flaw was discovered in the ext2 file system code. When a new directory is     created, the ext2 block written to disk is not initialized, which could     lead to an information leak if a disk image is made available to     unprivileged users. (CAN-2005-0400)

    A flaw in fragment queuing was discovered that affected the Linux kernel     netfilter subsystem. On systems configured to filter or process network     packets (e.g. firewalling), a remote attacker could send a carefully     crafted set of fragmented packets to a machine and cause a denial of     service (system crash). In order to sucessfully exploit this flaw, the     attacker would need to know or guess some aspects of the firewall ruleset     on the target system. (CAN-2005-0449)

    A number of flaws were found in the Linux 2.6 kernel. A local user could     use these flaws to read kernel memory or cause a denial of service (crash).
    (CAN-2005-0529, CAN-2005-0530, CAN-2005-0531)

    An integer overflow in sys_epoll_wait in eventpoll.c was discovered. A     local user could use this flaw to overwrite low kernel memory. This memory     is usually unused, not usually resulting in a security consequence.
    (CAN-2005-0736)

    A flaw when freeing a pointer in load_elf_library was discovered. A local     user could potentially use this flaw to cause a denial of service (crash).
    (CAN-2005-0749)

    A flaw was discovered in the bluetooth driver system. On systems where the     bluetooth modules are loaded, a local user could use this flaw to gain     elevated (root) privileges. (CAN-2005-0750)

    A race condition was discovered that affected the Radeon DRI driver. A     local user who has DRI privileges on a Radeon graphics card may be able to     use this flaw to gain root privileges. (CAN-2005-0767)

    Multiple range checking flaws were discovered in the iso9660 file system     handler. An attacker could create a malicious file system image which would     cause a denial or service or potentially execute arbitrary code if mounted.
    (CAN-2005-0815)

    A flaw was discovered when setting line discipline on a serial tty. A local     user may be able to use this flaw to inject mouse movements or keystrokes     when another user is logged in. (CAN-2005-0839)

    Red Hat Enterprise Linux 4 users are advised to upgrade their kernels     to the packages associated with their machine architectures and     configurations as listed in this erratum.

    Please note that

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote host is missing the patch for the advisory SUSE-SA:2005:018 (kernel).


The Linux kernel is the core component of the Linux system.

Several vulnerabilities were reported in the last few weeks which are fixed by this update.

ID	Name	Product	Family	Severity
22560	Debian DSA-1018-2 : kernel-source-2.4.27 - several vulnerabilities	Nessus	Debian Local Security Checks	high
22559	Debian DSA-1017-1 : kernel-source-2.6.8 - several vulnerabilities	Nessus	Debian Local Security Checks	critical
21928	CentOS 3 / 4 : kernel (CESA-2005:366)	Nessus	CentOS Local Security Checks	high
21923	CentOS 3 : kernel (CESA-2005:293)	Nessus	CentOS Local Security Checks	high
18161	RHEL 2.1 : kernel (RHSA-2005:283)	Nessus	Red Hat Local Security Checks	high
18128	RHEL 3 : kernel (RHSA-2005:293)	Nessus	Red Hat Local Security Checks	high
18095	RHEL 4 : kernel (RHSA-2005:366)	Nessus	Red Hat Local Security Checks	high
17617	SUSE-SA:2005:018: kernel	Nessus	SuSE Local Security Checks	high

Detections

Analytics

CVE-2005-0449

high

Tenable Plugins

high

critical

high

high

high

high

high

high