Integer overflow in the do_brk function for the brk system call in Linux kernel 2.4.22 and earlier allows local users to gain root privileges.

New kernels are available for Slackware 9.1 and -current. These have been upgraded to Linux kernel version 2.4.23, which fixes a bug in the kernel's do_brk() function that could be exploited to gain root privileges. These updated kernels and modules should be installed by any sites running a 2.4 kernel earlier than 2.4.23. Linux 2.0 and 2.2 kernels are not vulnerable.

Several local root exploits have been discovered recently in the Linux kernel. This security advisory updates the PA-RISC kernel 2.4.18 for Debian GNU/Linux. The Common Vulnerabilities and Exposures project identifies the following problems that are fixed with this update :

  - CAN-2003-0961 :
    An integer overflow in brk() system call (do_brk()     function) for Linux allows a local attacker to gain root     privileges. Fixed upstream in Linux 2.4.23.

  - CAN-2003-0985 :

    Paul Starzetz discovered a flaw in bounds checking in     mremap() in the Linux kernel (present in version 2.4.x     and 2.6.x) which may allow a local attacker to gain root     privileges. Version 2.2 is not affected by this bug.
    Fixed upstream in Linux 2.4.24.

  - CAN-2004-0077 :

    Paul Starzetz and Wojciech Purczynski of isec.pl     discovered a critical security vulnerability in the     memory management code of Linux inside the mremap(2)     system call. Due to missing function return value check     of internal functions a local attacker can gain root     privileges. Fixed upstream in Linux 2.4.25 and 2.6.3.

Please note that the source package has to include a lot of updates in order to compile the package, which wasn't possible with the old source package.

Several local root exploits have been discovered recently in the Linux kernel. This security advisory updates the hppa kernel 2.4.17 for Debian GNU/Linux. The Common Vulnerabilities and Exposures project identifies the following problems that are fixed with this update :

  - CAN-2003-0961 :
    An integer overflow in brk() system call (do_brk()     function) for Linux allows a local attacker to gain root     privileges. Fixed upstream in Linux 2.4.23.

  - CAN-2003-0985 :

    Paul Starzetz discovered a flaw in bounds checking in     mremap() in the Linux kernel (present in version 2.4.x     and 2.6.x) which may allow a local attacker to gain root     privileges. Version 2.2 is not affected by this bug.
    Fixed upstream in Linux 2.4.24.

  - CAN-2004-0077 :

    Paul Starzetz and Wojciech Purczynski of isec.pl     discovered a critical security vulnerability in the     memory management code of Linux inside the mremap(2)     system call. Due to missing function return value check     of internal functions a local attacker can gain root     privileges. Fixed upstream in Linux 2.4.25 and 2.6.3.

Several local root exploits have been discovered recently in the Linux kernel. This security advisory updates the mips kernel 2.4.19 for Debian GNU/Linux. The Common Vulnerabilities and Exposures project identifies the following problems that are fixed with this update :

  - CAN-2003-0961 :
    An integer overflow in brk() system call (do_brk()     function) for Linux allows a local attacker to gain root     privileges. Fixed upstream in Linux 2.4.23.

  - CAN-2003-0985 :

    Paul Starzetz discovered a flaw in bounds checking in     mremap() in the Linux kernel (present in version 2.4.x     and 2.6.x) which may allow a local attacker to gain root     privileges. Version 2.2 is not affected by this bug.
    Fixed upstream in Linux 2.4.24.

  - CAN-2004-0077 :

    Paul Starzetz and Wojciech Purczynski of isec.pl     discovered a critical security vulnerability in the     memory management code of Linux inside the mremap(2)     system call. Due to missing function return value check     of internal functions a local attacker can gain root     privileges. Fixed upstream in Linux 2.4.25 and 2.6.3.

Several security related problems have been fixed in the Linux kernel 2.4.17 used for the S/390 architecture, mostly by backporting fixes from 2.4.18 and incorporating recent security fixes. The corrections are listed below with the identification from the Common Vulnerabilities and Exposures (CVE) project :

  - CVE-2002-0429 :
    The iBCS routines in arch/i386/kernel/traps.c for Linux     kernels 2.4.18 and earlier on x86 systems allow local     users to kill arbitrary processes via a binary     compatibility interface (lcall).

  - CAN-2003-0001 :

    Multiple ethernet network interface card (NIC) device     drivers do not pad frames with null bytes, which allows     remote attackers to obtain information from previous     packets or kernel memory by using malformed packets, as     demonstrated by Etherleak.

  - CAN-2003-0244 :

    The route cache implementation in Linux 2.4, and the     Netfilter IP conntrack module, allows remote attackers     to cause a denial of service (CPU consumption) via     packets with forged source addresses that cause a large     number of hash table collisions related to the     PREROUTING chain.

  - CAN-2003-0246 :

    The ioperm system call in Linux kernel 2.4.20 and     earlier does not properly restrict privileges, which     allows local users to gain read or write access to     certain I/O ports.

  - CAN-2003-0247 :

    A vulnerability in the TTY layer of the Linux kernel 2.4     allows attackers to cause a denial of service ('kernel     oops').

  - CAN-2003-0248 :

    The mxcsr code in Linux kernel 2.4 allows attackers to     modify CPU state registers via a malformed address.

  - CAN-2003-0364 :

    The TCP/IP fragment reassembly handling in the Linux     kernel 2.4 allows remote attackers to cause a denial of     service (CPU consumption) via certain packets that cause     a large number of hash table collisions.

  - CAN-2003-0961 :

    An integer overflow in brk() system call (do_brk()     function) for Linux allows a local attacker to gain root     privileges. Fixed upstream in Linux 2.4.23.

  - CAN-2003-0985 :

    Paul Starzetz discovered a flaw in bounds checking in     mremap() in the Linux kernel (present in version 2.4.x     and 2.6.x) which may allow a local attacker to gain root     privileges. Version 2.2 is not affected by this bug.
    Fixed upstream in Linux 2.4.24.

  - CAN-2004-0077 :

    Paul Starzetz and Wojciech Purczynski of isec.pl     discovered a critical security vulnerability in the     memory management code of Linux inside the mremap(2)     system call. Due to missing function return value check     of internal functions a local attacker can gain root     privileges. Fixed upstream in Linux 2.4.25 and 2.6.3.

Several local root exploits have been discovered recently in the Linux kernel. This security advisory updates the PowerPC/Apus kernel for Debian GNU/Linux. The Common Vulnerabilities and Exposures project identifies the following problems that are fixed with this update :

  - CAN-2003-0961 :
    An integer overflow in brk() system call (do_brk()     function) for Linux allows a local attacker to gain root     privileges. Fixed upstream in Linux 2.4.23.

  - CAN-2003-0985 :

    Paul Starzetz discovered a flaw in bounds checking in     mremap() in the Linux kernel (present in version 2.4.x     and 2.6.x) which may allow a local attacker to gain root     privileges. Version 2.2 is not affected by this bug.
    Fixed upstream in Linux 2.4.24.

  - CAN-2004-0077 :

    Paul Starzetz and Wojciech Purczynski of isec.pl     discovered a critical security vulnerability in the     memory management code of Linux inside the mremap(2)     system call. Due to missing function return value check     of internal functions a local attacker can gain root     privileges. Fixed upstream in Linux 2.4.25 and 2.6.3.

Several local root exploits have been discovered recently in the Linux kernel. This security advisory updates the ARM kernel for Debian GNU/Linux. The Common Vulnerabilities and Exposures project identifies the following problems that are fixed with this update :

  - CAN-2003-0961 :
    An integer overflow in brk() system call (do_brk()     function) for Linux allows a local attacker to gain root     privileges. Fixed upstream in Linux 2.4.23.

  - CAN-2003-0985 :

    Paul Starzetz discovered a flaw in bounds checking in     mremap() in the Linux kernel (present in version 2.4.x     and 2.6.x) which may allow a local attacker to gain root     privileges. Version 2.2 is not affected by this bug.
    Fixed upstream in Linux 2.4.24.

  - CAN-2004-0077 :

    Paul Starzetz and Wojciech Purczynski of isec.pl     discovered a critical security vulnerability in the     memory management code of Linux inside the mremap(2)     system call. Due to missing function return value check     of internal functions a local attacker can gain root     privileges. Fixed upstream in Linux 2.4.25 and 2.6.3.

Red Hat and SuSE kernel and security teams revealed an integer overflow in the do_brk() function of the Linux kernel allows local users to gain root privileges.

The IA-64 maintainers fixed several security related bugs in the Linux kernel 2.4.17 used for the IA-64 architecture, mostly by backporting fixes from 2.4.18. The corrections are listed below with the identification from the Common Vulnerabilities and Exposures (CVE) project :

  - CAN-2003-0001 :
    Multiple ethernet network interface card (NIC) device     drivers do not pad frames with null bytes, which allows     remote attackers to obtain information from previous     packets or kernel memory by using malformed packets, as     demonstrated by Etherleak.

  - CAN-2003-0018 :

    Linux kernel 2.4.10 through 2.4.21-pre4 does not     properly handle the O_DIRECT feature, which allows local     attackers with write privileges to read portions of     previously deleted files, or cause file system     corruption.

  - CAN-2003-0127 :

    The kernel module loader in Linux kernel 2.2.x before     2.2.25, and 2.4.x before 2.4.21, allows local users to     gain root privileges by using ptrace to attach to a     child process which is spawned by the kernel.

  - CAN-2003-0461 :

    The virtual file /proc/tty/driver/serial in Linux 2.4.x     reveals the exact number of characters used in serial     links, which could allow local users to obtain     potentially sensitive information such as the length of     passwords.

  - CAN-2003-0462 :

    A race condition in the way env_start and env_end     pointers are initialized in the execve system call and     used in fs/proc/base.c on Linux 2.4 allows local users     to cause a denial of service (crash).

  - CAN-2003-0476 :

    The execve system call in Linux 2.4.x records the file     descriptor of the executable process in the file table     of the calling process, which allows local users to gain     read access to restricted file descriptors.

  - CAN-2003-0501 :

    The /proc filesystem in Linux allows local users to     obtain sensitive information by opening various entries     in /proc/self before executing a setuid program, which     causes the program to fail to change the ownership and     permissions of those entries.

  - CAN-2003-0550 :

    The STP protocol, as enabled in Linux 2.4.x, does not     provide sufficient security by design, which allows     attackers to modify the bridge topology.

  - CAN-2003-0551 :

    The STP protocol implementation in Linux 2.4.x does not     properly verify certain lengths, which could allow     attackers to cause a denial of service.

  - CAN-2003-0552 :

    Linux 2.4.x allows remote attackers to spoof the bridge     Forwarding table via forged packets whose source     addresses are the same as the target.

  - CAN-2003-0961 :

    An integer overflow in brk system call (do_brk function)     for Linux kernel 2.4.22 and earlier allows local users     to gain root privileges.

  - CAN-2003-0985 :

    The mremap system call (do_mremap) in Linux kernel 2.4     and 2.6 does not properly perform boundary checks, which     allows local users to cause a denial of service and     possibly gain privileges by causing a remapping of a     virtual memory area (VMA) to create a zero length VMA.

Paul Starzetz discovered a flaw in bounds checking in mremap() in the Linux kernel (present in version 2.4.x and 2.6.x) which may allow a local attacker to gain root privileges. Version 2.2 is not affected by this bug.

Andrew Morton discovered a missing boundary check for the brk system call which can be used to craft a local root exploit.

Recently multiple servers of the Debian project were compromised using a Debian developers account and an unknown root exploit. Forensics revealed a burneye encrypted exploit. Robert van der Meulen managed to decrypt the binary which revealed a kernel exploit. Study of the exploit by the Red Hat and SuSE kernel and security teams quickly revealed that the exploit used an integer overflow in the brk system call. Using this bug it is possible for a userland program to trick the kernel into giving access to the full kernel address space. This problem was found in September by Andrew Morton, but unfortunately that was too late for the 2.4.22 kernel release.

This bug has been fixed in kernel version 2.4.23 for the 2.4 tree and 2.6.0-test6 kernel tree. For Debian it has been fixed in version 2.4.18-14 of the kernel source packages, version 2.4.18-12 of the i386 kernel images and version 2.4.18-11 of the alpha kernel images.

A vulnerability was discovered in the Linux kernel versions 2.4.22 and previous. A flaw in bounds checking in the do_brk() function can allow a local attacker to gain root privileges. This vulnerability is known to be exploitable; an exploit is in the wild at this time.

The Mandrake Linux 9.2 kernels are not vulnerable to this problem as the fix for it is already present in kernel version 2.4.22-21mdk (provided in MDKA-2003:021).

MandrakeSoft encourages all users to upgrade their systems immediately.

To upgrade your kernel, please use the documentation available online :

http://www.mandrakesecure.net/en/kernelupdate.php

The remote host is missing the patch for the advisory SuSE-SA:2003:049 (Linux Kernel).


This security update fixes a serious vulnerability in the Linux kernel.  A missing bounds check in the brk() system call allowed processes to request memory beyond the maximum size allowed for tasks, causing kernel memory to be mapped into the process' address space.
This allowed local attackers to obtain super user privileges.

An exploit for this vulnerability is circulating in the wild, and has been used to compromise OpenSource development servers.

There is no temporary workaround for this bug.

This update also fixes several other security issues in the kernel

-	race condition with files opened via O_DIRECT which could be exploited to read disk blocks randomly. This could include blocks of previously deleted files with sensitive content.
-	don't allow users to send signals to kmod
-	when reading the RTC, don't leak kernel stack data to user space

Updated kernel packages are now available that fix a security vulnerability allowing local users to gain root privileges.

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

A flaw in bounds checking in the do_brk() function in the Linux kernel versions 2.4.22 and previous can allow a local attacker to gain root privileges. This issue is known to be exploitable; an exploit has been seen in the wild that takes advantage of this vulnerability. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2003-0961 to this issue.

All users of Red Hat Enterprise Linux 2.1 are advised to upgrade to these errata packages, which contain a backported security patch that corrects this vulnerability.

Users of Red Hat Enterprise Linux 3 should upgrade to the kernel packages provided by RHBA-2003:308 (released on 30 October 2003), which already contained a patch correcting this issue.

Updated kernel packages are now available that fix a security
vulnerability allowing local users to gain root privileges.

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

A flaw in bounds checking in the do_brk() function in the Linux kernel
versions 2.4.22 and previous can allow a local attacker to gain root
privileges. This issue is known to be exploitable; an exploit has been
seen in the wild that takes advantage of this vulnerability. The
Common Vulnerabilities and Exposures project (cve.mitre.org) has
assigned the name CVE-2003-0961 to this issue.

All users of Red Hat Enterprise Linux 2.1 are advised to upgrade to
these errata packages, which contain a backported security patch that
corrects this vulnerability.

Users of Red Hat Enterprise Linux 3 should upgrade to the kernel
packages provided by RHBA-2003:308 (released on 30 October 2003),
which already contained a patch correcting this issue.

ID	Name	Product	Family	Severity
18743	Slackware 9.1 / current : Kernel security update (SSA:2003-336-01)	Nessus	Slackware Local Security Checks	high
15312	Debian DSA-475-1 : linux-kernel-2.4.18-hppa - several vulnerabilities	Nessus	Debian Local Security Checks	high
15307	Debian DSA-470-1 : linux-kernel-2.4.17-hppa - several vulnerabilities	Nessus	Debian Local Security Checks	high
15287	Debian DSA-450-1 : linux-kernel-2.4.19-mips - several vulnerabilities	Nessus	Debian Local Security Checks	high
15279	Debian DSA-442-1 : linux-kernel-2.4.17-s390 - several vulnerabilities	Nessus	Debian Local Security Checks	critical
15277	Debian DSA-440-1 : linux-kernel-2.4.17-powerpc-apus - several vulnerabilities	Nessus	Debian Local Security Checks	high
15276	Debian DSA-439-1 : linux-kernel-2.4.16-arm - several vulnerabilities	Nessus	Debian Local Security Checks	high
15270	Debian DSA-433-1 : kernel-patch-2.4.17-mips - integer overflow	Nessus	Debian Local Security Checks	high
15260	Debian DSA-423-1 : linux-kernel-2.4.17-ia64 - several vulnerabilities	Nessus	Debian Local Security Checks	high
15254	Debian DSA-417-1 : linux-kernel-2.4.18-powerpc+alpha - missing boundary check	Nessus	Debian Local Security Checks	high
15240	Debian DSA-403-1 : kernel-image-2.4.18-1-alpha, kernel-image-2.4.18-1-i386, kernel-source-2.4.18 - local root exploit	Nessus	Debian Local Security Checks	high
14092	Mandrake Linux Security Advisory : kernel (MDKSA-2003:110)	Nessus	Mandriva Local Security Checks	high
13817	SuSE-SA:2003:049: Linux Kernel	Nessus	SuSE Local Security Checks	high
12438	RHEL 2.1 : kernel (RHSA-2003:389)	Nessus	Red Hat Local Security Checks	high
801583	Red Hat 2003-389 Security Check	Log Correlation Engine	Generic	high

Detections

Analytics

CVE-2003-0961

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Tenable Plugins

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critical

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