J-Security Center

Title: Multiple Sniffer Vendor DNS Decode Vulnerability

Severity: MODERATE

Description:

A vulnerability exists in the DNS decode capabilities provided as part of the tcpdump sniffer, from LBL, as well as other sniffers, including Ethereal, by Gerald Combs. These sniffers will attempt to decode DNS request and queries. However, due to the DNS name compression scheme, it is possible to create a DNS packet such that tcpdump will be caught in an infinite loop, while trying to decompress. This will prevent the sniffer from displaying further packets. If tcpdump is being used as some part of and intrusion detection system, this could allow an intruder to evade this system.

When tcpdump is logging to a file, it is not affected by this vulnerability. Upon reading from a file which contains recorded packets, it will enter an infinite loop when it encounters packets of this type.

Affected Products:

  • Debian Linux 2.2.0
  • Debian Linux 2.2.0 68k
  • Debian Linux 2.2.0 alpha
  • Debian Linux 2.2.0 arm
  • Debian Linux 2.2.0 powerpc
  • Debian Linux 2.2.0 sparc
  • Gerald Combs Ethereal 0.8.4
  • Gerald Combs Ethereal 0.8.5
  • Gerald Combs Ethereal 0.8.6
  • LBL tcpdump 3.4.0
  • LBL tcpdump 3.5.0 alpha
  • RedHat Linux 6.2.0 alpha
  • RedHat Linux 6.2.0 i386
  • RedHat Linux 6.2.0 sparc
  • RedHat Linux 7.0.0 alpha
  • RedHat Linux 7.0.0 i386
  • RedHat Linux 7.1.0 alpha
  • RedHat Linux 7.1.0 i386
  • RedHat Linux 7.1.0 ia64

Juniper Networks provides this content via a wide variety of sources and production methods. If notified of errors or omissions in the content of this page, Juniper Networks, at its discretion, will modify or remove the page or leave the content as is, depending on various factors including but not limited to the reputation and authority of the party providing the notification. Please use the contact information displayed elsewhere on this page to report any errors or omissions regarding the content on this page.