Chen Zhaojun of Alibaba Cloud Security Team discovered a critical security vulnerability in Apache Log4j, a popular Logging Framework for Java. JNDI features used in configuration, log messages, and parameters do not protect against attacker controlled LDAP and other JNDI related endpoints. An attacker who can control log messages or log message parameters can execute arbitrary code loaded from LDAP servers when message lookup substitution is enabled. From version 2.15.0, this behavior has been disabled by default.
This update also fixes CVE-2020-9488 in the oldstable distribution
(buster). Improper validation of certificate with host mismatch in Apache Log4j SMTP appender. This could allow an SMTPS connection to be intercepted by a man-in-the-middle attack which could leak any log messages sent through that appender.
For the oldstable distribution (buster), this problem has been fixed
in version 2.15.0-1~deb10u1.
For the stable distribution (bullseye), this problem has been fixed in
We recommend that you upgrade your apache-log4j2 packages.