Rapid7 Vulnerability & Exploit Database

Amazon Linux AMI 2: CVE-2019-17041: Security patch for rsyslog (ALAS-2020-1447)

Free InsightVM Trial No Credit Card Necessary
2024 Attack Intel Report Latest research by Rapid7 Labs
Back to Search

Amazon Linux AMI 2: CVE-2019-17041: Security patch for rsyslog (ALAS-2020-1447)

Severity
8
CVSS
(AV:N/AC:L/Au:N/C:P/I:P/A:P)
Published
10/07/2019
Created
07/03/2020
Added
07/02/2020
Modified
09/30/2022

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.

Solution(s)

  • amazon-linux-ami-2-upgrade-rsyslog
  • amazon-linux-ami-2-upgrade-rsyslog-crypto
  • amazon-linux-ami-2-upgrade-rsyslog-debuginfo
  • amazon-linux-ami-2-upgrade-rsyslog-doc
  • amazon-linux-ami-2-upgrade-rsyslog-elasticsearch
  • amazon-linux-ami-2-upgrade-rsyslog-gnutls
  • amazon-linux-ami-2-upgrade-rsyslog-gssapi
  • amazon-linux-ami-2-upgrade-rsyslog-kafka
  • amazon-linux-ami-2-upgrade-rsyslog-libdbi
  • amazon-linux-ami-2-upgrade-rsyslog-mmaudit
  • amazon-linux-ami-2-upgrade-rsyslog-mmjsonparse
  • amazon-linux-ami-2-upgrade-rsyslog-mmkubernetes
  • amazon-linux-ami-2-upgrade-rsyslog-mmnormalize
  • amazon-linux-ami-2-upgrade-rsyslog-mmsnmptrapd
  • amazon-linux-ami-2-upgrade-rsyslog-mysql
  • amazon-linux-ami-2-upgrade-rsyslog-pgsql
  • amazon-linux-ami-2-upgrade-rsyslog-relp
  • amazon-linux-ami-2-upgrade-rsyslog-snmp
  • amazon-linux-ami-2-upgrade-rsyslog-udpspoof

With Rapid7 live dashboards, I have a clear view of all the assets on my network, which ones can be exploited, and what I need to do in order to reduce the risk in my environment in real-time. No other tool gives us that kind of value and insight.

– Scott Cheney, Manager of Information Security, Sierra View Medical Center

;