CVE-2025-54812

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 v3 5.4 MEDIUM

5.4^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.3 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/apache/logging-log4cxx/pull/509	Issue Tracking Patch
https://github.com/apache/logging-log4cxx/pull/514	Issue Tracking Patch
https://logging.apache.org/security.html#CVE-2025-54812	Vendor Advisory
http://www.openwall.com/lists/oss-security/2025/08/22/2
https://lists.debian.org/debian-lts-announce/2025/10/msg00002.html

Configurations

Configuration 1 (hide)

cpe:2.3:a:apache:log4cxx:*:*:*:*:*:*:*:*

History

04 Nov 2025, 22:16

Type	Values Removed	Values Added
References		() http://www.openwall.com/lists/oss-security/2025/08/22/2 - () https://lists.debian.org/debian-lts-announce/2025/10/msg00002.html -

Information

Published : 2025-08-22 19:15

Updated : 2025-11-04 22:16

NVD link : CVE-2025-54812

Mitre link : CVE-2025-54812

CVE.ORG link : CVE-2025-54812

JSON object : View

Products Affected

apache

log4cxx

CWE

CWE-117

Improper Output Neutralization for Logs

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Al usar HTMLLayout, los nombres de registradores no se escapan correctamente al escribir en el archivo HTML. Si se usan datos no confiables para recuperar el nombre de un registrador, un atacante podr\u00eda, en teor\u00eda, inyectar HTML o Javascript para ocultar informaci\u00f3n de los registros o robar datos del usuario. Para activar esto, debe ocurrir la siguiente secuencia: * Log4cxx est\u00e1 configurado para usar HTMLLayout. * El nombre del registrador proviene de una cadena no confiable * El registrador con nombre comprometido registra un mensaje * El usuario abre el archivo de registro HTML generado en su navegador, lo que lleva a un posible XSS Debido a que los nombres de registradores generalmente son cadenas constantes, evaluamos el impacto para los usuarios como BAJO Este problema afecta a Apache Log4cxx: antes de 1.5.0. Se recomienda a los usuarios actualizar a la versi\u00f3n 1.5.0, que soluciona el problema."}], "lastModified": "2025-11-04T22:16:29.313", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:apache:log4cxx:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8E1443DD-B968-4005-A287-964C6197FEB0", "versionEndExcluding": "1.5.0"}], "operator": "OR"}]}], "sourceIdentifier": "[email protected]"}