CVE-2021-45046

Name	CVE-2021-45046
Description	It was found that the fix to address CVE-2021-44228 in Apache Log4j 2.15.0 was incomplete in certain non-default configurations. This could allows attackers with control over Thread Context Map (MDC) input data when the logging configuration uses a non-default Pattern Layout with either a Context Lookup (for example, $${ctx:loginId}) or a Thread Context Map pattern (%X, %mdc, or %MDC) to craft malicious input data using a JNDI Lookup pattern resulting in an information leak and remote code execution in some environments and local code execution in all environments. Log4j 2.16.0 (Java 8) and 2.12.2 (Java 7) fix this issue by removing support for message lookup patterns and disabling JNDI functionality by default.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DSA-5022-1
Debian Bugs	1001729

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
apache-log4j2 (PTS)	buster	2.17.1-1~deb10u1	fixed
	buster (security)	2.17.0-1~deb10u1	fixed
	bullseye	2.17.1-1~deb11u1	fixed
	bullseye (security)	2.17.0-1~deb11u1	fixed
	sid, trixie, bookworm	2.19.0-2	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Origin	Debian Bugs
apache-log4j2	source	stretch	(not affected)
apache-log4j2	source	buster	2.16.0-1~deb10u1	DSA-5022-1
apache-log4j2	source	bullseye	2.16.0-1~deb11u1	DSA-5022-1
apache-log4j2	source	(unstable)	2.16.0-1		1001729

Notes

[stretch] - apache-log4j2 <not-affected> (JndiLookup class has been removed)
https://www.openwall.com/lists/oss-security/2021/12/14/4
https://logging.apache.org/log4j/2.x/security.html#CVE-2021-45046
https://issues.apache.org/jira/browse/LOG4J2-3221
https://www.lunasec.io/docs/blog/log4j-zero-day-update-on-cve-2021-45046/