PHP <8.0.30/8.1.22/8.2.8 libxml External Entity Exposure
CVE-2023-3823 Published on August 11, 2023
Security issue with external entity loading in XML without enabling it
In PHP versions 8.0.* before 8.0.30, 8.1.* before 8.1.22, and 8.2.* before 8.2.8 various XML functions rely on libxml global state to track configuration variables, like whether external entities are loaded. This state is assumed to be unchanged unless the user explicitly changes it by calling appropriate function. However, since the state is process-global, other modules - such as ImageMagick - may also use this library within the same process, and change that global state for their internal purposes, and leave it in a state where external entities loading is enabled. This can lead to the situation where external XML is parsed with external entities loaded, which can lead to disclosure of any local files accessible to PHP. This vulnerable state may persist in the same process across many requests, until the process is shut down.
Vulnerability Analysis
CVE-2023-3823 can be exploited 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.
Products Associated with CVE-2023-3823
You can be notified by email with stack.watch whenever vulnerabilities like CVE-2023-3823 are published in these products:
Affected Versions
PHP Group PHP:- Version 8.0.* and below 8.0.30 is affected.
- Version 8.1.* and below 8.1.22 is affected.
- Version 8.2.* and below 8.2.8 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.