Bug#1001478: apache-log4j2: CVE-2021-44228:: Remote code injection via crafted log messages

[Salvatore Bonaccorso]

Source: apache-log4j2
Version: 2.13.3-1
Severity: grave
Tags: security upstream
Justification: user security hole
Forwarded: https://issues.apache.org/jira/browse/LOG4J2-3198 https://github.com/apache/logging-log4j2/pull/608
X-Debbugs-Cc: carnil at debian.org, Debian Security Team <team at security.debian.org>
Control: found -1 2.11.1-2
Control: found -1 2.7-2

Hi,

The following vulnerability was published for apache-log4j2.

I'm still choosing grave for the severity, though there are some
mitigating factors depending on the Java version used. See for details
the references, in particular [3].

Additionally according to latest comments in [4] the issue seems not
to be completely fixed. As the lookup is performed after formatting
the message, which includes the user input, the vulnerability could
still be triggered using a ParametrizedMessage. See [4] the comments
from Eric Everman and Volkan Yazici.

CVE-2021-44228[0]:
| Apache Log4j2 <=2.14.1 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
| log4j 2.15.0, this behavior has been disabled by default. In previous
| releases (>2.10) this behavior can be mitigated by setting system
| property "log4j2.formatMsgNoLookups" to &#8220;true&#8221; or
| by removing the JndiLookup class from the classpath (example: zip -q
| -d log4j-core-*.jar
| org/apache/logging/log4j/core/lookup/JndiLookup.class). Java 8u121
| (see
| https://www.oracle.com/java/technologies/javase/8u121-relnotes.html)
| protects against remote code execution by defaulting
| "com.sun.jndi.rmi.object.trustURLCodebase" and
| "com.sun.jndi.cosnaming.object.trustURLCodebase" to "false".


If you fix the vulnerability please also make sure to include the
CVE (Common Vulnerabilities & Exposures) id in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2021-44228
    https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-44228
[1] https://github.com/advisories/GHSA-jfh8-c2jp-5v3q
[2] https://github.com/apache/logging-log4j2/pull/608
[3] https://www.lunasec.io/docs/blog/log4j-zero-day/
[4] https://issues.apache.org/jira/browse/LOG4J2-3198

Regards,
Salvatore