Intelligence online17 sources monitored8 actively exploited 7d26 published 24hChecked recently
Vulnerability record

CVE-2021-45046

Apache Log4j2 Deserialization of Untrusted Data Vulnerability

CriticalExploitation confirmedCISA KEV Used by ransomware
What should I do?

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it. If you run Log4j2, fix it now.

CISA required action: Apply updates per vendor instructions.

US federal civilian agencies must remediate by May 22, 2023.

Patch status

Official fix available since

Apply the vendor's update to every affected system. Check the fixed-in versions below where known.

Basis: NVD patch reference

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: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.

Affected products

ProductVendorAffected versionsFixed inSource
Log4j2Apache Software Foundation——KEV
SonicWall Email SecuritySonicWall< 10.0.1210.0.12NVD

Sources: KEV = CISA Known Exploited Vulnerabilities catalog; NVD = NIST National Vulnerability Database.

Intelligence timeline

Developments from the last 30 days, newest first.

  1. CVSS scoredUpdateKEV

    CVE-2021-45046 scored CVSS 9.0: Apache Log4j2, Apache Log4j2 Deserialization of Untrusted Data Vulnerability

    CISA lists this as exploited in the wild and known to be used in ransomware campaigns. Unpatched Log4j2 systems are exposed to active attacks now.

    Basis: NIST National Vulnerability Database

  2. Patch releasedUpdateKEV

    Patch released for CVE-2021-45046: Apache Log4j2, Apache Log4j2 Deserialization of Untrusted Data Vulnerability

    An official fix is now available for Apache Log4j2. This vulnerability is being exploited, so apply it promptly.

    Basis: NVD patch reference

1 earlier event is available with a subscription. See plans.

Coverage

We have not published a story about this vulnerability yet.

References