Apache HTTP Server 2.4.63 mod_ssl log injection via unsanitized SSL var
CVE-2024-47252 Published on July 10, 2025
Apache HTTP Server: mod_ssl error log variable escaping
Insufficient escaping of user-supplied data in mod_ssl in Apache HTTP Server 2.4.63 and earlier allows an untrusted SSL/TLS client to insert escape characters into log files in some configurations.
In a logging configuration where CustomLog is used with "%{varname}x" or "%{varname}c" to log variables provided by mod_ssl such as SSL_TLS_SNI, no escaping is performed by either mod_log_config or mod_ssl and unsanitized data provided by the client may appear in log files.
Vulnerability Analysis
CVE-2024-47252 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity and availability.
Timeline
reported
Weakness Type
Improper Neutralization of Escape, Meta, or Control Sequences
The software receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as escape, meta, or control character sequences when they are sent to a downstream component. As data is parsed, an injected/absent/malformed delimiter may cause the process to take unexpected actions.
Products Associated with CVE-2024-47252
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Affected Versions
Apache Software Foundation Apache HTTP Server:- Version 2.4, <= 2.4.63 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.