Exploited vulnerability · CISA KEV

Is CVE-2021-45046 exploited? Yes: in CISA KEV since 1 May 2023

Gociux · Apache Log4j2 · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2021-45046, Apache Log4j2 Deserialization of Untrusted Data Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 1 May 2023, 503 days after it was published. It is known to be used in ransomware campaigns. It affects Apache Log4j2. If you run it, CISA's required action is: Apply updates per vendor instructions.

What it is

Apache Log4j2 contains a deserialization of untrusted data vulnerability due to the incomplete fix of CVE-2021-44228, where the Thread Context Lookup Pattern is vulnerable to remote code execution in certain non-default configurations.

What to do

1. Check whether you run it. Look for Log4j2 in your asset inventory, including appliances and cloud images. Stack check lists every exploited Apache CVE at once.
2. Apply the fix. Apply updates per vendor instructions.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 14 Dec 2021.
4. Get told next time. Email alerts when CISA adds a CVE for Apache.

Other exploited CVEs in Log4j2

• CVE-2021-44228: Apache Log4j2 Remote Code Execution Vulnerability (10 Dec 2021)

References

• logging.apache.org/log4j/2.x/security.html
• nvd.nist.gov/vuln/detail/CVE-2021-45046

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in May 2023 · Apache scorecard · act-now radar.