The ip_push_pending_frames function in Linux 2.4.x and 2.6.x before 2.6.16 increments the IP ID field when sending a RST after receiving unsolicited TCP SYN-ACK packets, which allows remote attackers to conduct an Idle Scan (nmap -sI) attack, which bypasses intended protections against such attacks.

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-2005-3359     Franz Filz discovered that some socket calls permit     causing inconsistent reference counts on loadable     modules, which allows local users to cause a denial of     service.

  - CVE-2006-0038     'Solar Designer' discovered that arithmetic computations     in netfilter's do_replace() function can lead to a     buffer overflow and the execution of arbitrary code.
    However, the operation requires CAP_NET_ADMIN     privileges, which is only an issue in virtualization     systems or fine grained access control systems.

  - CVE-2006-0039     'Solar Designer' discovered a race condition in     netfilter's do_add_counters() function, which allows     information disclosure of kernel memory by exploiting a     race condition. Likewise, it requires CAP_NET_ADMIN     privileges. 

  - CVE-2006-0456     David Howells discovered that the s390 assembly version     of the strnlen_user() function incorrectly returns some     string size values.

  - CVE-2006-0554     It was discovered that the ftruncate() function of XFS     can expose unallocated blocks, which allows information     disclosure of previously deleted files.

  - CVE-2006-0555     It was discovered that some NFS file operations on     handles mounted with O_DIRECT can force the kernel into     a crash.

  - CVE-2006-0557     It was discovered that the code to configure memory     policies allows tricking the kernel into a crash, thus     allowing denial of service.

  - CVE-2006-0558     It was discovered by Cliff Wickman that perfmon for the     IA64 architecture allows users to trigger a BUG()     assert, which allows denial of service.

  - CVE-2006-0741     Intel EM64T systems were discovered to be susceptible to     a local DoS due to an endless recursive fault related to     a bad ELF entry address.

  - CVE-2006-0742     Alan and Gareth discovered that the ia64 platform had an     incorrectly declared die_if_kernel() function as 'does     never return' which could be exploited by a local     attacker resulting in a kernel crash.

  - CVE-2006-0744     The Linux kernel did not properly handle uncanonical     return addresses on Intel EM64T CPUs, reporting     exceptions in the SYSRET instead of the next     instruction, causing the kernel exception handler to run     on the user stack with the wrong GS. This may result in     a DoS due to a local user changing the frames.

  - CVE-2006-1056     AMD64 machines (and other 7th and 8th generation     AuthenticAMD processors) were found to be vulnerable to     sensitive information leakage, due to how they handle     saving and restoring the FOP, FIP, and FDP x87 registers     in FXSAVE/FXRSTOR when an exception is pending. This     allows a process to determine portions of the state of     floating point instructions of other processes.

  - CVE-2006-1242     Marco Ivaldi discovered that there was an unintended     information disclosure allowing remote attackers to     bypass protections against Idle Scans (nmap -sI) by     abusing the ID field of IP packets and bypassing the     zero IP ID in DF packet countermeasure. This was a     result of the ip_push_pending_frames function improperly     incremented the IP ID field when sending a RST after     receiving unsolicited TCP SYN-ACK packets.

  - CVE-2006-1368     Shaun Tancheff discovered a buffer overflow (boundary     condition error) in the USB Gadget RNDIS implementation     allowing remote attackers to cause a DoS. While creating     a reply message, the driver allocated memory for the     reply data, but not for the reply structure. The kernel     fails to properly bounds-check user-supplied data before     copying it to an insufficiently sized memory buffer.
    Attackers could crash the system, or possibly execute     arbitrary machine code.

  - CVE-2006-1523     Oleg Nesterov reported an unsafe BUG_ON call in signal.c     which was introduced by RCU signal handling. The BUG_ON     code is protected by siglock while the code in     switch_exit_pids() uses tasklist_lock. It may be     possible for local users to exploit this to initiate a     denial of service attack (DoS).

  - CVE-2006-1524     Hugh Dickins discovered an issue in the madvise_remove()     function wherein file and mmap restrictions are not     followed, allowing local users to bypass IPC permissions     and replace portions of readonly tmpfs files with     zeroes.

  - CVE-2006-1525     Alexandra Kossovsky reported a NULL pointer dereference     condition in ip_route_input() that can be triggered by a     local user by requesting a route for a multicast IP     address, resulting in a denial of service (panic).

  - CVE-2006-1857     Vlad Yasevich reported a data validation issue in the     SCTP subsystem that may allow a remote user to overflow     a buffer using a badly formatted HB-ACK chunk, resulting     in a denial of service.

  - CVE-2006-1858     Vlad Yasevich reported a bug in the bounds checking code     in the SCTP subsystem that may allow a remote attacker     to trigger a denial of service attack when rounded     parameter lengths are used to calculate parameter     lengths instead of the actual values.

  - CVE-2006-1863     Mark Mosely discovered that chroots residing on an CIFS     share can be escaped with specially crafted 'cd'     sequences.

  - CVE-2006-1864     Mark Mosely discovered that chroots residing on an SMB     share can be escaped with specially crafted 'cd'     sequences.

  - CVE-2006-2271     The 'Mu security team' discovered that carefully crafted     ECNE chunks can cause a kernel crash by accessing     incorrect state stable entries in the SCTP networking     subsystem, which allows denial of service.

  - CVE-2006-2272     The 'Mu security team' discovered that fragmented SCTP     control chunks can trigger kernel panics, which allows     for denial of service attacks.

  - CVE-2006-2274     It was discovered that SCTP packets with two initial     bundled data packets can lead to infinite recursion,     which allows for denial of service attacks.

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-2006-0038     'Solar Designer' discovered that arithmetic computations     in netfilter's do_replace() function can lead to a     buffer overflow and the execution of arbitrary code.
    However, the operation requires CAP_NET_ADMIN     privileges, which is only an issue in virtualization     systems or fine grained access control systems.

  - CVE-2006-0039     'Solar Designer' discovered a race condition in     netfilter's do_add_counters() function, which allows     information disclosure of kernel memory by exploiting a     race condition. Like CVE-2006-0038, it requires     CAP_NET_ADMIN privileges.

  - CVE-2006-0741     Intel EM64T systems were discovered to be susceptible to     a local DoS due to an endless recursive fault related to     a bad ELF entry address.

  - CVE-2006-0742     Incorrectly declared die_if_kernel() function as 'does     never return' which could be exploited by a local     attacker resulting in a kernel crash.

  - CVE-2006-1056     AMD64 machines (and other 7th and 8th generation     AuthenticAMD processors) were found to be vulnerable to     sensitive information leakage, due to how they handle     saving and restoring the FOP, FIP, and FDP x87 registers     in FXSAVE/FXRSTOR when an exception is pending. This     allows a process to determine portions of the state of     floating point instructions of other processes.

  - CVE-2006-1242     Marco Ivaldi discovered that there was an unintended     information disclosure allowing remote attackers to     bypass protections against Idle Scans (nmap -sI) by     abusing the ID field of IP packets and bypassing the     zero IP ID in DF packet countermeasure. This was a     result of the ip_push_pending_frames function improperly     incremented the IP ID field when sending a RST after     receiving unsolicited TCP SYN-ACK packets.

  - CVE-2006-1343     Pavel Kankovsky reported the existence of a potential     information leak resulting from the failure to     initialize sin.sin_zero in the IPv4 socket code.

  - CVE-2006-1368     Shaun Tancheff discovered a buffer overflow (boundary     condition error) in the USB Gadget RNDIS implementation     allowing remote attackers to cause a DoS. While creating     a reply message, the driver allocated memory for the     reply data, but not for the reply structure. The kernel     fails to properly bounds-check user-supplied data before     copying it to an insufficiently sized memory buffer.
    Attackers could crash the system, or possibly execute     arbitrary machine code.

  - CVE-2006-1524     Hugh Dickins discovered an issue in the madvise_remove()     function wherein file and mmap restrictions are not     followed, allowing local users to bypass IPC permissions     and replace portions of readonly tmpfs files with     zeroes.

  - CVE-2006-1525     Alexandra Kossovsky reported a NULL pointer dereference     condition in ip_route_input() that can be triggered by a     local user by requesting a route for a multicast IP     address, resulting in a denial of service (panic).

  - CVE-2006-1857     Vlad Yasevich reported a data validation issue in the     SCTP subsystem that may allow a remote user to overflow     a buffer using a badly formatted HB-ACK chunk, resulting     in a denial of service.

  - CVE-2006-1858     Vlad Yasevich reported a bug in the bounds checking code     in the SCTP subsystem that may allow a remote attacker     to trigger a denial of service attack when rounded     parameter lengths are used to calculate parameter     lengths instead of the actual values.

  - CVE-2006-1864     Mark Mosely discovered that chroots residing on an SMB     share can be escaped with specially crafted 'cd'     sequences.

  - CVE-2006-2271     The 'Mu security team' discovered that carefully crafted     ECNE chunks can cause a kernel crash by accessing     incorrect state stable entries in the SCTP networking     subsystem, which allows denial of service.

  - CVE-2006-2272     The 'Mu security team' discovered that fragmented SCTP     control chunks can trigger kernel panics, which allows     for denial of service attacks.

  - CVE-2006-2274     It was discovered that SCTP packets with two initial     bundled data packets can lead to infinite recursion,     which allows for denial of service attacks.

Updated kernel packages are now available as part of ongoing support and maintenance of Red Hat Enterprise Linux version 4.

This update 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 fourth regular update to Red Hat Enterprise Linux 4.

New features introduced in this update include :

* Device Mapper mirroring support

* IDE diskdump support

* x86, AMD64 and Intel EM64T: Multi-core scheduler support enhancements

* Itanium: perfmon support for Montecito

* much improved support for IBM x460

* AMD PowerNow! patches to support Opteron Rev G

* Vmalloc support > 64MB

The following device drivers have been upgraded to new versions :

ipmi: 33.11 to 33.13 ib_mthca: 0.06 to 0.08 bnx2: 1.4.30 to 1.4.38 bonding: 2.6.1 to 2.6.3 e100: 3.4.8-k2-NAPI to 3.5.10-k2-NAPI e1000:
6.1.16-k3-NAPI to 7.0.33-k2-NAPI sky2: 0.13 to 1.1 tg3: 3.43-rh to 3.52-rh ipw2100: 1.1.0 to git-1.1.4 ipw2200: 1.0.0 to git-1.0.10 3w-9xxx: 2.26.02.001 to 2.26.04.010 ips: 7.10.18 to 7.12.02 iscsi_sfnet: 4:0.1.11-2 to 4:0.1.11-3 lpfc: 0:8.0.16.18 to 0:8.0.16.27 megaraid_sas: 00.00.02.00 to 00.00.02.03-RH1 qla2xxx: 8.01.02-d4 to 8.01.04-d7 qla6312: 8.01.02-d4 to 8.01.04-d7 sata_promise: 1.03 to 1.04 sata_vsc: 1.1 to 1.2 ibmvscsic: 1.5.5 to 1.5.6 ipr: 2.0.11.1 to 2.0.11.2

Added drivers :

dcdbas: 5.6.0-2 sata_mv: 0.6 sata_qstor: 0.05 sata_uli: 0.5 skge: 1.1 stex: 2.9.0.13 pdc_adma: 0.03

This update includes fixes for the security issues :

* a flaw in the USB devio handling of device removal that allowed a local user to cause a denial of service (crash) (CVE-2005-3055, moderate)

* a flaw in the ACL handling of nfsd that allowed a remote user to bypass ACLs for readonly mounted NFS file systems (CVE-2005-3623, moderate)

* a flaw in the netfilter handling that allowed a local user with CAP_NET_ADMIN rights to cause a buffer overflow (CVE-2006-0038, low)

* a flaw in the IBM S/390 and IBM zSeries strnlen_user() function that allowed a local user to cause a denial of service (crash) or to retrieve random kernel data (CVE-2006-0456, important)

* a flaw in the keyctl functions that allowed a local user to cause a denial of service (crash) or to read sensitive kernel memory (CVE-2006-0457, important)

* a flaw in unaligned accesses handling on Itanium processors that allowed a local user to cause a denial of service (crash) (CVE-2006-0742, important)

* a flaw in SELinux ptrace logic that allowed a local user with ptrace permissions to change the tracer SID to a SID of another process (CVE-2006-1052, moderate)

* an info leak on AMD-based x86 and x86_64 systems that allowed a local user to retrieve the floating point exception state of a process run by a different user (CVE-2006-1056, important)

* a flaw in IPv4 packet output handling that allowed a remote user to bypass the zero IP ID countermeasure on systems with a disabled firewall (CVE-2006-1242, low)

* a minor info leak in socket option handling in the network code (CVE-2006-1343, low)

* a flaw in the HB-ACK chunk handling of SCTP that allowed a remote user to cause a denial of service (crash) (CVE-2006-1857, moderate)

* a flaw in the SCTP implementation that allowed a remote user to cause a denial of service (deadlock) (CVE-2006-2275, moderate)

* a flaw in the socket buffer handling that allowed a remote user to cause a denial of service (panic) (CVE-2006-2446, important)

* a flaw in the signal handling access checking on PowerPC that allowed a local user to cause a denial of service (crash) or read arbitrary kernel memory on 64-bit systems (CVE-2006-2448, important)

* a flaw in the netfilter SCTP module when receiving a chunkless packet that allowed a remote user to cause a denial of service (crash) (CVE-2006-2934, important)

There were several 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 4.

Updated kernel packages are now available as part of ongoing support and maintenance of Red Hat Enterprise Linux version 3. This is the eighth 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 eighth regular kernel update to Red Hat Enterprise Linux 3.

New features introduced by this update include :

  - addition of the adp94xx and dcdbas device drivers -     diskdump support on megaraid_sas, qlogic, and swap     partitions - support for new hardware via driver and     SCSI white-list updates

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 3.

There were numerous driver updates and security fixes (elaborated below). Other key areas affected by fixes in this update include the networking subsystem, the NFS and autofs4 file systems, the SCSI and USB subsystems, and architecture-specific handling affecting AMD Opteron and Intel EM64T processors.

The following device drivers have been added or upgraded to new versions :

adp94xx -------- 1.0.8 (new) bnx2 ----------- 1.4.38 cciss ---------- 2.4.60.RH1 dcdbas --------- 5.6.0-1 (new) e1000 ---------- 7.0.33-k2 emulex --------- 7.3.6 forcedeth ------ 0.30 ipmi ----------- 35.13 qlogic --------- 7.07.04b6 tg3 ------------ 3.52RH

The following security bugs were fixed in this update :

  - a flaw in the USB devio handling of device removal that     allowed a local user to cause a denial of service     (crash) (CVE-2005-3055, moderate)

  - a flaw in the exec() handling of multi-threaded tasks     using ptrace() that allowed a local user to cause a     denial of service (hang of a user process)     (CVE-2005-3107, low)

  - a difference in 'sysretq' operation of EM64T (as opposed     to Opteron) processors that allowed a local user to     cause a denial of service (crash) upon return from     certain system calls (CVE-2006-0741 and CVE-2006-0744,     important)

  - a flaw in unaligned accesses handling on Intel Itanium     processors that allowed a local user to cause a denial     of service (crash) (CVE-2006-0742, important)

  - an info leak on AMD-based x86 and x86_64 systems that     allowed a local user to retrieve the floating point     exception state of a process run by a different user     (CVE-2006-1056, important)

  - a flaw in IPv4 packet output handling that allowed a     remote user to bypass the zero IP ID countermeasure on     systems with a disabled firewall (CVE-2006-1242, low)

  - a minor info leak in socket option handling in the     network code (CVE-2006-1343, low)

  - a flaw in IPv4 netfilter handling for the unlikely use     of SNMP NAT processing that allowed a remote user to     cause a denial of service (crash) or potential memory     corruption (CVE-2006-2444, moderate)

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

All Red Hat Enterprise Linux 3 users are advised to upgrade their kernels to the packages associated with their machine architectures and configurations as listed in this erratum.

A number of vulnerabilities were discovered and corrected in the Linux 2.6 kernel :

Prior to Linux kernel 2.6.16.5, the kernel does not properly handle uncanonical return addresses on Intel EM64T CPUs which causes the kernel exception handler to run on the user stack with the wrong GS (CVE-2006-0744).

The selinux_ptrace logic hooks in SELinux for 2.6.6 allow local users with ptrace permissions to change the tracer SID to an SID of another process (CVE-2006-1052).

Prior to 2.6.16, the ip_push_pending_frames function increments the IP ID field when sending a RST after receiving unsolicited TCP SYN-ACK packets, which allows a remote attacker to conduct an idle scan attack, bypassing any intended protection against such an attack (CVE-2006-1242).

In kernel 2.6.16.1 and some earlier versions, the sys_add_key function in the keyring code allows local users to cause a DoS (OOPS) via keyctl requests that add a key to a user key instead of a keyring key, causing an invalid dereference (CVE-2006-1522).

Prior to 2.6.16.8, the ip_route_input function allows local users to cause a DoS (panic) via a request for a route for a multicast IP address, which triggers a null dereference (CVE-2006-1525).

Prior to 2.6.16.13, the SCTP-netfilter code allows remote attackers to cause a DoS (infinite loop) via unknown vectors that cause an invalid SCTP chunk size to be processed (CVE-2006-1527).

Prior to 2.6.16, local users can bypass IPC permissions and modify a read-only attachment of shared memory by using mprotect to give write permission to the attachment (CVE-2006-2071).

Prior to 2.6.17, the ECNE chunk handling in SCTP (lksctp) allows remote attackers to cause a DoS (kernel panic) via an unexpected chucnk when the session is in CLOSED state (CVE-2006-2271).

Prior to 2.6.17, SCTP (lksctp) allows remote attacker to cause a DoS (kernel panic) via incoming IP fragmented COOKIE_ECHO and HEARTBEAT SCTP control chunks (CVE-2006-2272).

In addition to these security fixes, other fixes have been included such as :

  - fix a scheduler deadlock

    - Yenta oops fix

    - ftdi_sio: adds support for iPlus devices

    - enable kprobes on i386 and x86_64

    - avoid a panic on bind mount of autofs owned directory

    - fix a kernel OOPs when booting with 'console=ttyUSB0'       but without a USB-serial dongle plugged in

  - make dm-mirror not issue invalid resync requests

    - fix media change detection on scsi removable devices

    - add support for the realtek 8168 chipset

    - update hfsplus driver to 2.6.16 state

    - backport 'Gilgal' support from e1000 7.0.33

    - selected ACPI video fixes

    - update 3w-9xxx to 2.26.02.005 (9550SX support)

    - fix a deadlock in the ext2 filesystem

    - fix usbserial use-after-free bug

    - add i945GM DRI support

    - S3 resume fixes

    - add ECS PF22 hda model support

    - SMP suspend

    - CPU hotplug

    - miscellaneous AGP fixes

    - added sata-suspend patch for 2.6.12 for Napa platform

The provided packages are patched to fix these vulnerabilities. All users are encouraged to upgrade to these updated kernels.

As well, updated mkinitrd and bootsplash packages are provided to fix minor issues; users should upgrade both packages prior to installing a new kernel.

To update your kernel, please follow the directions located at :

http://www.mandriva.com/en/security/kernelupdate

The sys_mbind() function did not properly verify the validity of the 'maxnod' argument. A local user could exploit this to trigger a buffer overflow, which caused a kernel crash. (CVE-2006-0557)

The SELinux module did not correctly handle the tracer SID when a process was already being traced. A local attacker could exploit this to cause a kernel crash. (CVE-2006-1052)

Al Viro discovered a local Denial of Service in the sysfs write buffer handling. By writing a block with a length exactly equal to the processor's page size to any writable file in /sys, a local attacker could cause a kernel crash. (CVE-2006-1055)

John Blackwood discovered a race condition with single-step debugging multiple processes at the same time. A local attacker could exploit this to crash the system. This only affects the amd64 platform.
(CVE-2006-1066)

Marco Ivaldi discovered a flaw in the handling of the ID number of IP packets. This number was incremented after receiving unsolicited TCP SYN-ACK packets. A remote attacker could exploit this to conduct port scans with the 'Idle scan' method (nmap -sI), which bypassed intended port scan protections. (CVE-2006-1242)

Pavel Kankovsky discovered that the getsockopt() function, when called with an SO_ORIGINAL_DST argument, does not properly clear the returned structure, so that a random piece of kernel memory is exposed to the user. This could potentially reveal sensitive data like passwords or encryption keys. (CVE-2006-1343)

A buffer overflow was discovered in the USB Gadget RNDIS implementation. While creating a reply message, the driver did not allocate enough memory for the reply structure. A remote attacker could exploit this to cause a kernel crash. (CVE-2006-1368)

Alexandra Kossovsky discovered an invalid memory access in the ip_route_input() function. By using the 'ip' command in a particular way to retrieve multicast routes, a local attacker could exploit this to crash the kernel. (CVE-2006-1525).

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

The remote CentOS system is missing a security update which has been documented in Red Hat advisory RHSA-2006-0575.

The remote CentOS system is missing a security update which has been documented in Red Hat advisory RHSA-2006-0437.

ID	Name	Product	Family	Severity
22645	Debian DSA-1103-1 : kernel-source-2.6.8 - several vulnerabilities	Nessus	Debian Local Security Checks	critical
22639	Debian DSA-1097-1 : kernel-source-2.4.27 - several vulnerabilities	Nessus	Debian Local Security Checks	critical
22276	CentOS 4 : kernel (CESA-2006:0575)	Nessus	CentOS Local Security Checks	high
22221	RHEL 4 : kernel (RHSA-2006:0575)	Nessus	Red Hat Local Security Checks	high
22135	CentOS 3 : kernel (CESA-2006:0437)	Nessus	CentOS Local Security Checks	high
22086	RHEL 3 : kernel (RHSA-2006:0437)	Nessus	Red Hat Local Security Checks	high
21575	Mandrake Linux Security Advisory : kernel (MDKSA-2006:086)	Nessus	Mandriva Local Security Checks	high
21375	Ubuntu 5.04 / 5.10 : linux-source-2.6.10, linux-source-2.6.12 vulnerabilities (USN-281-1)	Nessus	Ubuntu Local Security Checks	critical
801420	CentOS RHSA-2006-0575 Security Check	Log Correlation Engine	Generic	high
801417	CentOS RHSA-2006-0437 Security Check	Log Correlation Engine	Generic	high

Detections

Analytics

CVE-2006-1242

high

Tenable Plugins

critical

critical

high

high

high

high

high

critical

high

high