Buffer overflow in sysctl in the Linux Kernel 2.6 before 2.6.15 allows local users to corrupt user memory and possibly cause a denial of service via a long string, which causes sysctl to write a zero byte outside the buffer. NOTE: since the sysctl is called from a userland program that provides the argument, this might not be a vulnerability, unless a legitimate user-assisted or setuid scenario can be identified.

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.

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

The udp_v6_get_port function in udp.c, when running IPv6, allows local users to cause a Denial of Service (infinite loop and crash) (CVE-2005-2973).

The mq_open system call in certain situations can decrement a counter twice as a result of multiple calls to the mntput function when the dentry_open function call fails, allowing a local user to cause a DoS (panic) via unspecified attack vectors (CVE-2005-3356).

The procfs code allows attackers to read sensitive kernel memory via unspecified vectors in which a signed value is added to an unsigned value (CVE-2005-4605).

A buffer overflow in sysctl allows local users to cause a DoS and possibly execute arbitrary code via a long string, which causes sysctl to write a zero byte outside the buffer (CVE-2005-4618).

A buffer overflow in the CA-driver for TwinHan DST Frontend/Card allows local users to cause a DoS (crash) and possibly execute arbitrary code by reading more than eight bytes into an eight byte long array (CVE-2005-4639).

dm-crypt does not clear a structure before it is freed, which leads to a memory disclosure that could allow local users to obtain sensitive information about a cryptographic key (CVE-2006-0095).

Remote attackers can cause a DoS via unknown attack vectors related to an 'extra dst release when ip_options_echo fails' in icmp.c (CVE-2006-0454).

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

  - support for mptsas

    - fix for IPv6 with sis190

    - a problem with the time progressing twice as fast

    - a fix for Audigy 2 ZS Video Editor sample rates

    - a fix for a supermount crash when accessing a       supermount-ed CD/DVD drive

  - a fix for improperly unloading sbp2 module

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

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

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

Doug Chapman discovered a flaw in the reference counting in the sys_mq_open() function. By calling this function in a special way, a local attacker could exploit this to cause a kernel crash.
(CVE-2005-3356)

Karl Janmar discovered that the /proc file system module used signed data types in a wrong way. A local attacker could exploit this to read random kernel memory, which could possibly contain sensitive data like passwords or private keys. (CVE-2005-4605)

Yi Yang discovered an off-by-one buffer overflow in the sysctl() system call. By calling sysctl with a specially crafted long string, a local attacker could exploit this to crash the kernel or possibly even execute arbitrary code with full kernel privileges. (CVE-2005-4618)

Perceval Anichini found a buffer overflow in the TwinHan DST Frontend/Card DVB driver. A local user could exploit this to crash the kernel or possibly execute arbitrary code with full kernel privileges.
This only affects Ubuntu 5.10. (CVE-2005-4639)

Stefan Rompf discovered that the dm-crypt module did not clear memory structures before releasing the memory allocation of it. This could lead to the disclosure of encryption keys. (CVE-2006-0095)

The SDLA WAN driver did not restrict firmware upgrades to processes that have the CAP_SYS_RAWIO kernel capability, it just required the CAP_NET_ADMIN privilege. This could allow processes with the latter privilege to update the SDLA firmware. Please note that this does not affect a standard Ubuntu installation, and this cannot be exploited by a normal (unprivileged) user. At most, this flaw might be relevant for installations that use a fine-grained capability granting system like RSBAC, cap_over, or grsecurity. This only affects Ubuntu 4.10.
(CVE-2006-0096).

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.

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
20939	Mandrake Linux Security Advisory : kernel (MDKSA-2006:040)	Nessus	Mandriva Local Security Checks	medium
20791	Ubuntu 4.10 / 5.04 / 5.10 : linux-source-2.6.8.1/-2.6.10/-2.6.12 vulnerabilities (USN-244-1)	Nessus	Ubuntu Local Security Checks	high

Detections

Analytics

CVE-2005-4618

high

Tenable Plugins

high

critical

medium

high