{"id":86873,"date":"2026-04-05T07:14:09","date_gmt":"2026-04-05T07:14:09","guid":{"rendered":""},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-30T00:00:00","slug":"cve-2025-54813-improper-output-neutralization-in-apache-log4cxx-leads-to-potential-system-compromise","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-54813-improper-output-neutralization-in-apache-log4cxx-leads-to-potential-system-compromise\/","title":{"rendered":"CVE-2025-54813: Improper Output Neutralization in Apache Log4cxx Leads to Potential System Compromise<\/strong>"},"content":{"rendered":"

Overview<\/strong><\/p>\n

The CVE-2025-54813 vulnerability exposes systems to potential compromise due to improper output neutralization for logs in Apache Log4cxx. It specifically affects versions of Apache Log4cxx prior to 1.5.0. As a result, attackers can exploit this vulnerability to hinder the correct interpretation of log information by applications that consume these logs, thereby leading to system compromise or data leakage.<\/p>\n

Vulnerability Summary<\/strong><\/p>\n

CVE ID: CVE-2025-54813
\nSeverity: High (CVSS 7.5)
\nAttack Vector: Network
\nPrivileges Required: None
\nUser Interaction: None
\nImpact: Potential system compromise or data leakage<\/p>\n

Affected Products<\/strong><\/p>\n

Product | Affected Versions<\/p>\n

Apache Log4cxx | Before 1.5.0<\/p>\n

How the Exploit Works<\/strong><\/p>\n

This vulnerability arises from a failure to properly escape all payload bytes when using JSONLayout. If an attacker supplies a message with specific non-printable characters, these characters are included in the message and written out as part of the JSON message. This prevents applications that consume these logs from correctly interpreting the information, leading to potential system compromise or data leakage.<\/p>\n

Conceptual Example Code<\/strong><\/p>\n

The conceptual exploit of this vulnerability might involve an attacker sending a message containing non-printable characters. This could be achieved through an HTTP POST request as shown below:<\/p>\n

POST \/log4cxx\/endpoint HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/json\n{ \"message\": \"Hello\\u001b[31m World\" }<\/code><\/pre>\n
In the above conceptual example, the string “\\u001b[31m” is a non-printable character sequence that could potentially disrupt the correct interpretation of log information by applications that consume these logs. The specific impact would depend on how the receiving application handles such characters.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview The CVE-2025-54813 vulnerability exposes systems to potential compromise due to improper output neutralization for logs in Apache Log4cxx. It specifically affects versions of Apache Log4cxx prior to 1.5.0. As a result, attackers can exploit this vulnerability to hinder the correct interpretation of log information by applications that consume these logs, thereby leading to system […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[],"tags":[],"vendor":[],"product":[],"attack_vector":[],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-86873","post","type-post","status-publish","format-standard","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t