CVE-2019-17041

rsyslog: heap-based overflow in contrib/pmaixforwardedfrom/pmaixforwardedfrom.c

Published Oct 7, 2019 CVSS 3.1 · 9.8 Critical EPSS 4.4% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-1952-1 rsyslog security update
Debian DLA Debian DLA DLA-2835-1 rsyslog security update
EUVD EUVD EUVD-2019-7515 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.
Ubuntu USN Ubuntu USN USN-5419-1 Rsyslog vulnerabilities
History

No history.

Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Aug 5, 2024, 1:24 AM
Reserved
Sep 30, 2019, 12:00 AM
Status
Modified
Published
Oct 7, 2019, 4:15 PM
Modified
Jun 17, 2026, 2:23 AM
Severity
Moderate
Public date
Sep 30, 2019, 12:00 AM