CVE-2019-17041: An issue was discovered in Rsyslog v8.1908.0. contrib/pmaixforwardedfrom/pmaixforwardedfrom.c has a heap overflow in the parser for AIX log messages. ...

Description

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.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

4.57%

90.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-787

Affected Software

Vendor	Product	Versions
Rsyslog	Rsyslog	8.1908.0
Debian	Debian Linux	9.0
Fedoraproject	Fedora	30
Fedoraproject	Fedora	31
Opensuse	Leap	15.0
Opensuse	Leap	15.1

References

http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00031.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00032.htmlMailing List, Third Party Advisory
https://github.com/rsyslog/rsyslog/blob/v8-stable/ChangeLogRelease Notes, Third Party Advisory
https://github.com/rsyslog/rsyslog/pull/3884Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/11/msg00030.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KPNCHI7X2IEXRH6RYD6IDPR4PLB5RPC7/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/W6SUQE25RD37CD24BHKUWMG27U5RQ2FU/
http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00031.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00032.htmlMailing List, Third Party Advisory
https://github.com/rsyslog/rsyslog/blob/v8-stable/ChangeLogRelease Notes, Third Party Advisory
https://github.com/rsyslog/rsyslog/pull/3884Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/11/msg00030.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KPNCHI7X2IEXRH6RYD6IDPR4PLB5RPC7/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/W6SUQE25RD37CD24BHKUWMG27U5RQ2FU/

Timeline

Published: Oct 7, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-17041?

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.

How severe is CVE-2019-17041?

CVE-2019-17041 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 4.57% probability of exploitation in the next 30 days.

How do I fix CVE-2019-17041?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.