LSH file descriptor leak information disclosure and denial of service

lsh-file-descriptor-leak (24263) The risk level is classified as LowLow Risk

Description:

LSH leaks file descriptors of the random generator seed file to user shells that are started by lshd. This could allow a local attacker to cause a denial of service by truncating the seed file, or obtain sensitive information that could be used to crack session keys.


Consequences:

Obtain Information

Remedy:

For vendor-supplied patch, refer to the lsh-bugs Mailing List posting dated Fri Jan 20 17:44:07 CET 2006. See References.

For Debian GNU/Linux:
Refer to DSA-956-1 for patch, upgrade, or suggested workaround information. See References.

References:

  • lsh Web page: LSH - a GNU implementation of the Secure Shells protocols.
  • lsh-bugs Mailing List, Fri Jan 20 17:44:07 CET 2006: SECURITY: lshd leaks fd:s to user shells.
  • BID-16357: LSH Seed File File Descriptor Leakage Vulnerability
  • CVE-2006-0353: unix_random.c in lshd for lsh 2.0.1 leaks file descriptors related to the randomness generator, which allows local users to cause a denial of service by truncating the seed file, which prevents the server from starting, or obtain sensitive seed information that could be used to crack keys.
  • DSA-956: lsh-server -- filedescriptor leak
  • OSVDB ID: 22695: LSH lshd Seed-file File Descriptor Leak
  • SA18564: LSH lshd Seed-file File Descriptor Leak Vulnerability
  • VUPEN/ADV-2006-0301: LSH lshd Seed-file Information Disclosure and Denial of Service Issue

Platforms Affected:

  • Debian Debian Linux 3.1
  • GNU LSH 2.0.1

Reported:

Jan 20, 2006

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