Log4shell vulnerability triggered (RCE) - CVE-2021-44228

Tactic:

このページは日本語には対応しておりません。随時翻訳に取り組んでいます。翻訳に関してご質問やご意見ございましたら、お気軽にご連絡ください。

Detect successful exploits of the Log4shell vulnerability (CVE-2021-44228).

The vulnerability has CVSS Score: 10.0 CRITICAL and can lead to Remote Code Execution (RCE).

Monitor payloads matching known patterns for CVE-2021-44228 (event rule: #sqr-000-017 ) and lookup for HTTP requests to load a Java class.

Generate an Application Security signal with CRITICAL severity.

Consider blocking the attacking IP(s) temporarily to prevent them to reach deeper parts of your production systems.

Considering the targeted application uses a vulnerable version of log4j and the default settings are disabled:

Update log4j to the latest patched version immediately (>= 2.15.0)
Disable lookups by setting formatMsgNoLookups=true. Only available from log4j >= 2.10 versions
Use a non-vulnerable or empty implementation of the class org.apache.logging.log4j.core.lookup.JndiLookup
Investigate the logs and the external class that is being called in the attack to check if the attacker successfully executed arbitrary code or not.