CVE-2019-17041

Published: 07 October 2019

An issue was discovered in Rsyslog v8.1908.0. contrib/pmaixforwardedfrom/pmaixforwardedfrom.c has a heap overflow in the parser for AIX log messages. The parser tries to locate a log message delimiter (in this case, a space or a colon) but fails to account for strings that do not satisfy this constraint. If the string does not match, then the variable lenMsg will reach the value zero and will skip the sanity check that detects invalid log messages. The message will then be considered valid, and the parser will eat up the nonexistent colon delimiter. In doing so, it will decrement lenMsg, a signed integer, whose value was zero and now becomes minus one. The following step in the parser is to shift left the contents of the message. To do this, it will call memmove with the right pointers to the target and destination strings, but the lenMsg will now be interpreted as a huge value, causing a heap overflow.

Priority

Low

CVSS 3 base score: 9.8

Status

Package Release Status
rsyslog
Launchpad, Ubuntu, Debian
Upstream
Released (8.1910.0-1)
Ubuntu 21.04 (Hirsute Hippo) Not vulnerable
(8.2001.0-1ubuntu1)
Ubuntu 20.04 LTS (Focal Fossa) Not vulnerable
(8.2001.0-1ubuntu1)
Ubuntu 18.04 LTS (Bionic Beaver) Needed

Ubuntu 16.04 ESM (Xenial Xerus) Needed

Ubuntu 14.04 ESM (Trusty Tahr) Needs triage

Notes

AuthorNote
mdeslaur
requires pmaixforwardedfrom module to be loaded, which is not
enabled in the default configuration

References

Bugs