Certain modifications to the Linux kernel 2.6.16 and earlier do not add the appropriate Linux Security Modules (LSM) file_permission hooks to the (1) readv and (2) writev functions, which might allow attackers to bypass intended access restrictions.

An integer overflow was discovered in the do_replace() function. A local user process with the CAP_NET_ADMIN capability could exploit this to execute arbitrary commands with full root privileges. However, none of Ubuntu's supported packages use this capability with any non-root user, so this only affects you if you use some third party software like the OpenVZ virtualization system. (CVE-2006-0038)

On EMT64 CPUs, the kernel did not properly handle uncanonical return addresses. A local user could exploit this to trigger a kernel crash.
(CVE-2006-0744)

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)

Jan Beulich discovered an information leak in the handling of registers for the numeric coprocessor when running on AMD processors.
This allowed processes to see the coprocessor execution state of other processes, which could reveal sensitive data in the case of cryptographic computations. (CVE-2006-1056)

Marcel Holtmann discovered that the sys_add_key() did not check that a new user key is added to a proper keyring. By attempting to add a key to a normal user key (which is not a keyring), a local attacker could exploit this to crash the kernel. (CVE-2006-1522)

Ingo Molnar discovered that the SCTP protocol connection tracking module in netfilter got stuck in an infinite loop on certain empty packet chunks. A remote attacker could exploit this to cause the computer to hang. (CVE-2006-1527)

The SCSI I/O driver did not correctly handle the VM_IO flag for memory mapped pages used for data transfer. A local user could exploit this to cause a kernel crash. (CVE-2006-1528)

The choose_new_parent() contained obsolete debugging code. A local user could exploit this to cause a kernel crash. (CVE-2006-1855)

Kostik Belousov discovered that the readv() and writev() functions did not query LSM modules for access permission. This could be exploited to circumvent access restrictions defined by LSM modules such as SELinux or AppArmor. (CVE-2006-1856)

The SCTP driver did not properly verify certain parameters when receiving a HB-ACK chunk. By sending a specially crafted packet to an SCTP socket, a remote attacker could exploit this to trigger a buffer overflow, which could lead to a crash or possibly even arbitrary code execution. (CVE-2006-1857)

The sctp_walk_params() function in the SCTP driver incorrectly used rounded values for bounds checking instead of the precise values. By sending a specially crafted packet to an SCTP socket, a remote attacker could exploit this to crash the kernel. (CVE-2006-1858)

Bjoern Steinbrink reported a memory leak in the __setlease() function.
A local attacker could exploit this to exhaust kernel memory and render the computer unusable (Denial of Service). (CVE-2006-1859)

Daniel Hokka Zakrisson discovered that the lease_init() did not properly handle locking. A local attacker could exploit this to cause a kernel deadlock (Denial of Service). (CVE-2006-1860)

Mark Moseley discovered that the CIFS file system driver did not filter out '..\\' path components. A local attacker could exploit this to break out of a chroot environment on a mounted SMB share.
(CVE-2006-1863) The same vulnerability applies to the older smb file system. (CVE-2006-1864)

Hugh Dickins discovered that the mprotect() function allowed an user to change a read-only shared memory attachment to become writable, which bypasses IPC (inter-process communication) permissions.
(CVE-2006-2071)

The SCTP (Stream Control Transmission Protocol) driver triggered a kernel panic on unexpected packets while the session was in the CLOSED state, instead of silently ignoring the packets. A remote attacker could exploit this to crash the computer. (CVE-2006-2271)

The SCTP driver did not handle control chunks if they arrived in fragmented packets. By sending specially crafted packets to an SCTP socket, a remote attacker could exploit this to crash the target machine. (CVE-2006-2272)

The SCTP driver did not correctly handle packets containing more than one DATA fragment. By sending specially crafted packets to an SCTP socket, a remote attacker could exploit this to crash the target machine. (CVE-2006-2274)

The SCTP driver did not correcly buffer incoming packets. By sending a large number of small messages to a receiver application that cannot process the messages quickly enough, a remote attacker could exploit this to cause a deadlock in the target machine (Denial of Service).
(CVE-2006-2275)

Patrick McHardy discovered that the snmp_trap_decode() function did not correctly handle memory allocation in some error conditions. By sending specially crafted packets to a machine which uses the SNMP network address translation (NAT), a remote attacker could exploit this to crash that machine. (CVE-2006-2444)

In addition, the Ubuntu 6.06 LTS update fixes a range of bugs.

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.

This advisory covers the S/390 components of the recent security update for the Linux 2.6.8 kernel that were missing due to technical problems. For reference, please see the text of the original advisory.

  Several security related problems have been discovered in the Linux   kernel which may lead to a denial of service or even the execution   of arbitrary code. The Common Vulnerabilities and Exposures project   identifies the following problems :

    - CVE-2004-2660       Toshihiro Iwamoto discovered a memory leak in the       handling of direct I/O writes that allows local users       to cause a denial of service.

    - CVE-2005-4798       A buffer overflow in NFS readlink handling allows a       malicious remote server to cause a denial of service.

    - CVE-2006-1052       Stephen Smalley discovered a bug in the SELinux ptrace       handling that allows local users with ptrace       permissions to change the tracer SID to the SID of       another process.

    - CVE-2006-1343       Pavel Kankovsky discovered an information leak in the       getsockopt system call which can be exploited by a       local program to leak potentially sensitive memory to       userspace.

    - CVE-2006-1528       Douglas Gilbert reported a bug in the sg driver that       allows local users to cause a denial of service by       performing direct I/O transfers from the sg driver to       memory mapped I/O space.

    - CVE-2006-1855       Mattia Belletti noticed that certain debugging code       left in the process management code could be exploited       by a local attacker to cause a denial of service.

    - CVE-2006-1856       Kostik Belousov discovered a missing LSM       file_permission check in the readv and writev       functions which might allow attackers to bypass       intended access restrictions.

    - CVE-2006-2444       Patrick McHardy discovered a bug in the SNMP NAT       helper that allows remote attackers to cause a denial       of service.

    - CVE-2006-2446       A race condition in the socket buffer handling allows       remote attackers to cause a denial of service.

    - CVE-2006-2935       Diego Calleja Garcia discovered a buffer overflow in       the DVD handling code that could be exploited by a       specially crafted DVD USB storage device to execute       arbitrary code.

    - CVE-2006-2936       A bug in the serial USB driver has been discovered       that could be exploited by a custom made USB serial       adapter to consume arbitrary amounts of memory.

    - CVE-2006-3468       James McKenzie discovered a denial of service       vulnerability in the NFS driver. When exporting an       ext3 file system over NFS, a remote attacker could       exploit this to trigger a file system panic by sending       a specially crafted UDP packet.

    - CVE-2006-3745       Wei Wang discovered a bug in the SCTP implementation       that allows local users to cause a denial of service       and possibly gain root privileges.

    - CVE-2006-4093       Olof Johansson discovered that the kernel does not       disable the HID0 bit on PowerPC 970 processors which       could be exploited by a local attacker to cause a       denial of service.

    - CVE-2006-4145       A bug in the Universal Disk Format (UDF) filesystem       driver could be exploited by a local user to cause a       denial of service.

    - CVE-2006-4535       David Miller reported a problem with the fix for       CVE-2006-3745 that allows local users to crash the       system via an SCTP socket with a certain SO_LINGER       value.

The following matrix explains which kernel version for which architecture fixes the problem mentioned above :

                              stable (sarge)                 Source                       2.6.8-16sarge5                 Alpha architecture           2.6.8-16sarge5                 AMD64 architecture           2.6.8-16sarge5                 HP Precision architecture    2.6.8-6sarge5                  Intel IA-32 architecture     2.6.8-16sarge5                 Intel IA-64 architecture     2.6.8-14sarge5                 Motorola 680x0 architecture  2.6.8-4sarge5                  PowerPC architecture         2.6.8-12sarge5                 IBM S/390                    2.6.8-5sarge5                  Sun Sparc architecture       2.6.8-15sarge5                 FAI                          1.9.1sarge4

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

The kernel did not clear sockaddr_in.sin_zero before returning IPv4 socket names for the getsockopt function, which could allow a local user to obtain portions of potentially sensitive memory if getsockopt() is called with SO_ORIGINAL_DST (CVE-2006-1343).

Prior to 2.6.16, a buffer overflow in the USB Gadget RNDIS implementation could allow a remote attacker to cause a Denial of Service via a remote NDIS response (CVE-2006-1368).

Prior to 2.6.13, local users could cause a Denial of Service (crash) via a dio transfer from the sg driver to memory mapped IO space (CVE-2006-1528).

Prior to and including 2.6.16, the kernel did not add the appropriate LSM file_permission hooks to the readv and writev functions, which could allow an attacker to bypass intended access restrictions (CVE-2006-1856).

Prior to 2.6.16.17, a buffer oveflow in SCTP could allow a remote attacker to cause a DoS (crash) and possibly execute arbitrary code via a malformed HB-ACK chunk (CVE-2006-1857).

Prior to 2.6.16.17, SCTP could allow a remote attacker to cause a DoS (crash) and possibly execute arbitrary code via a chunk length that is inconsistent with the actual length of provided parameters (CVE-2006-1858).

Prior to 2.6.16.16, a memory leak in fs/locks.c could allow an attacker to cause a DoS (memory consumption) via unspecified actions (CVE-2006-1859).

Prior to 2.6.16.16, lease_init in fs/locks.c could allow an attacker to cause a DoS (fcntl_setlease lockup) via certain actions (CVE-2006-1860).

Prior to 2.6.17, SCTP allowed remote attackers to cause a DoS (infinite recursion and crash) via a packet that contains two or more DATA fragments (CVE-2006-2274).

Prior to 2.6.16.21, a race condition in run_posix_cpu timers could allow a local user to cause a DoS (BUG_ON crash) by causing one CPU to attach a timer to a process that is exiting (CVE-2006-2445).

Prior to 2.6.17.1, xt_sctp in netfilter could allow an attacker to cause a DoS (infinite loop) via an SCTP chunk with a 0 length (CVE-2006-3085).

As well, an issue where IPC could hit an unmapped vmalloc page when near the page boundary has been corrected.

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

  - avoid automatic update of kernel-source without updating     the kernel

    - fix USB EHCI handoff code, which made some machines       hang while booting

  - disable USB_BANDWIDTH which corrects a known problem in     some USB sound devices

  - fix a bluetooth refcounting bug which could hang the     machine

    - fix a NULL pointer dereference in USB-Serial's       serial_open() function

  - add missing wakeup in pl2303 TIOCMIWAIT handling

    - fix a possible user-after-free in USB-Serial core

    - suspend/resume fixes

    - HPET timer fixes

    - prevent fixed button event to reach userspace on S3       resume

    - add sysfs support in ide-tape

    - fix ASUS P5S800 reboot

Finally, a new drbd-utils package is provided that is a required upgrade with this new kernel due to a logic bug in the previously shipped version of drbd-utils that could cause a kernel panic on the master when a slave went offline.

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

Updated kernel packages that fix several security issues in the Red Hat Enterprise Linux 4 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.

These new kernel packages contain fixes for the security issues described below :

* a flaw in the IPv6 implementation that allowed a local user to cause a denial of service (infinite loop and crash) (CVE-2005-2973, important)

* a flaw in the bridge implementation that allowed a remote user to cause forwarding of spoofed packets via poisoning of the forwarding table with already dropped frames (CVE-2005-3272, moderate)

* a flaw in the atm module that allowed a local user to cause a denial of service (panic) via certain socket calls (CVE-2005-3359, important)

* a flaw in the NFS client implementation that allowed a local user to cause a denial of service (panic) via O_DIRECT writes (CVE-2006-0555, important)

* 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 the keyring implementation that allowed a local user to cause a denial of service (OOPS) (CVE-2006-1522, important)

* a flaw in IP routing implementation that allowed a local user to cause a denial of service (panic) via a request for a route for a multicast IP (CVE-2006-1525, important)

* a flaw in the SCTP-netfilter implementation that allowed a remote user to cause a denial of service (infinite loop) (CVE-2006-1527, important)

* a flaw in the sg driver that allowed a local user to cause a denial of service (crash) via a dio transfer to memory mapped (mmap) IO space (CVE-2006-1528, important)

* a flaw in the threading implementation that allowed a local user to cause a denial of service (panic) (CVE-2006-1855, important)

* two missing LSM hooks that allowed a local user to bypass the LSM by using readv() or writev() (CVE-2006-1856, moderate)

* a flaw in the virtual memory implementation that allowed local user to cause a denial of service (panic) by using the lsof command (CVE-2006-1862, important)

* a directory traversal vulnerability in smbfs that allowed a local user to escape chroot restrictions for an SMB-mounted filesystem via '..\\' sequences (CVE-2006-1864, moderate)

* a flaw in the ECNE chunk handling of SCTP that allowed a remote user to cause a denial of service (panic) (CVE-2006-2271, moderate)

* a flaw in the handling of COOKIE_ECHO and HEARTBEAT control chunks of SCTP that allowed a remote user to cause a denial of service (panic) (CVE-2006-2272, moderate)

* a flaw in the handling of DATA fragments of SCTP that allowed a remote user to cause a denial of service (infinite recursion and crash) (CVE-2006-2274, moderate)

All 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.

The remote CentOS system is missing a security update which has been documented in Red Hat advisory RHSA-2006-0493.

ID	Name	Product	Family	Severity
27877	Ubuntu 5.04 / 5.10 / 6.06 LTS : linux-source-2.6.10/2.6.12/2.6.15 vulnerabilities (USN-302-1)	Nessus	Ubuntu Local Security Checks	high
22726	Debian DSA-1184-2 : kernel-source-2.6.8 - several vulnerabilities	Nessus	Debian Local Security Checks	high
22058	Mandrake Linux Security Advisory : kernel (MDKSA-2006:123)	Nessus	Mandriva Local Security Checks	critical
21997	CentOS 4 : kernel (CESA-2006:0493)	Nessus	CentOS Local Security Checks	high
21592	RHEL 4 : kernel (RHSA-2006:0493)	Nessus	Red Hat Local Security Checks	high
801418	CentOS RHSA-2006-0493 Security Check	Log Correlation Engine	Generic	high

Detections

Analytics

CVE-2006-1856

critical

Tenable Plugins

high

high

critical

high

high

high