Vulnerability Description
Improper Output Neutralization for Logs vulnerability in Apache Log4cxx. When using HTMLLayout, logger names are not properly escaped when writing out to the HTML file. If untrusted data is used to retrieve the name of a logger, an attacker could theoretically inject HTML or Javascript in order to hide information from logs or steal data from the user. In order to activate this, the following sequence must occur: * Log4cxx is configured to use HTMLLayout. * Logger name comes from an untrusted string * Logger with compromised name logs a message * User opens the generated HTML log file in their browser, leading to potential XSS Because logger names are generally constant strings, we assess the impact to users as LOW This issue affects Apache Log4cxx: before 1.5.0. Users are recommended to upgrade to version 1.5.0, which fixes the issue.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Apache | Log4Cxx | < 1.5.0 |
Related Weaknesses (CWE)
References
- https://github.com/apache/logging-log4cxx/pull/509Issue TrackingPatch
- https://github.com/apache/logging-log4cxx/pull/514Issue TrackingPatch
- https://logging.apache.org/security.html#CVE-2025-54812Vendor Advisory
- http://www.openwall.com/lists/oss-security/2025/08/22/2
- https://lists.debian.org/debian-lts-announce/2025/10/msg00002.html
FAQ
What is CVE-2025-54812?
CVE-2025-54812 is a vulnerability with a CVSS score of 5.4 (MEDIUM). Improper Output Neutralization for Logs vulnerability in Apache Log4cxx. When using HTMLLayout, logger names are not properly escaped when writing out to the HTML file. If untrusted data is used to ...
How severe is CVE-2025-54812?
CVE-2025-54812 has been rated MEDIUM with a CVSS base score of 5.4/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-54812?
Check the references section above for vendor advisories and patch information. Affected products include: Apache Log4Cxx.