CVE-2019-17042
Published: 7 October 2019
An issue was discovered in Rsyslog v8.1908.0. contrib/pmcisconames/pmcisconames.c has a heap overflow in the parser for Cisco 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.
Notes
| Author | Note |
|---|---|
| mdeslaur | requires pmcisconames module to be loaded, which is not enabled in the default configuration |
Priority
Status
| Package | Release | Status |
|---|---|---|
|
rsyslog Launchpad, Ubuntu, Debian |
bionic |
Needed
|
| disco |
Ignored
(reached end-of-life)
|
|
| eoan |
Ignored
(reached end-of-life)
|
|
| focal |
Not vulnerable
(8.2001.0-1ubuntu1)
|
|
| groovy |
Not vulnerable
(8.2001.0-1ubuntu1)
|
|
| hirsute |
Not vulnerable
(8.2001.0-1ubuntu1)
|
|
| impish |
Not vulnerable
(8.2001.0-1ubuntu1)
|
|
| jammy |
Not vulnerable
(8.2001.0-1ubuntu1)
|
|
| kinetic |
Not vulnerable
(8.2001.0-1ubuntu1)
|
|
| lunar |
Not vulnerable
(8.2001.0-1ubuntu1)
|
|
| trusty |
Needs triage
|
|
| upstream |
Released
(8.1910.0-1)
|
|
| xenial |
Released
(8.16.0-1ubuntu3.1+esm1)
|
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 9.8 |
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity impact | High |
| Availability impact | High |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |