CVE-2023-3823

CVE-2023-3823 is a high-severity vulnerability in Php with a CVSS 3.x base score of 8.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-611.

Key facts

Description

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.

Frequently asked questions

What is CVE-2023-3823?
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.
How severe is CVE-2023-3823?
CVE-2023-3823 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability low.
Is CVE-2023-3823 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-3823?
CVE-2023-3823 primarily affects Php. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-3823?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-3823 published?
CVE-2023-3823 was published on 2023-08-11 and last updated on 2026-06-17.

References

Affected products (3)

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Threat intelligence

Threat-intel indicators referencing this CVE: