CERT-In Vulnerability Note CIVN-2008-84
Linux Kernel ASN.1 BER Decoding Vulnerability

Original Issue Date: June 13, 2008

Severity Rating: Medium

System Affected

• Linux Kernel versions prior to 2.4.36.6 of the 2.4 branch
• Linux Kernel version 2.6.25.5 of the 2.6 branch

Overview

A vulnerability has been reported in two Linux kernel modules, CIFS file system and ip_nat_snmp_basic in the ASN.1 decoder when handling length BER encodings

Description

A vulnerability has been reported in the Linux Kernel ASN.1 decoder affecting the CIFS and ip_nat_snmp_basic modules when configured to use SLOB and SLUB kernel memory allocators, resulting in a heap overflow and arbitrary code execution. This can be exploited by malicious people to cause DoS (Denial of Service) and potentially compromise a system.

Solution

Update to a fixed version

• For Linux Kernel 2.4 branch:
  Update to version 2.4.36.6 or later
  
  
• For Linux Kernel 2.6 branch:
  Update to version 2.6.25.5 or later

Vendor Information

Kernel
http://kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.25.5
http://kernel.org/pub/linux/kernel/v2.4/ChangeLog-2.4.36.6

References

Secunia
http://secunia.com/advisories/30580

NVD
http://nvd.nist.gov/nvd.cfm?cvename=CVE-2008-1673

Redhat
https://bugzilla.redhat.com/show_bug.cgi?id=443962

IBM ISS
http://xforce.iss.net/xforce/xfdb/42921

CVE Name
CVE-2008-1673

Disclaimer

The information provided herein is on "as is" basis, without warranty of any kind.

Contact Information

Phone: +91-11-24368572

Postal address

Indian Computer Emergency Response Team (CERT-In)
Ministry of Communications and Information Technology
Electronics Niketan
6, C.G.O. Complex
New Delhi-110 003