Service crash via worker-count allocation integer overflow
Published Nov 2, 2023 · Updated Nov 3, 2025
Heap buffer overflow in PHP's CLI server on affected Red Hat and Fedora Linux releases allows local users to crash the server. php_cli_server_startup_workers converts PHP_CLI_SERVER_WORKERS without a safe allocation bound, so worker-count multiplication can wrap and allocate an undersized PID array that later writes overflow. Exploitation requires control of the process environment before the built-in server starts; the supported consequence is a service crash.
Summary
What happened
Heap buffer overflow in PHP's CLI server on affected Red Hat and Fedora Linux releases allows local users to crash the server. php_cli_server_startup_workers converts PHP_CLI_SERVER_WORKERS without a safe allocation bound, so worker-count multiplication can wrap and allocate an undersized PID array that later writes overflow. Exploitation requires control of the process environment before the built-in server starts; the supported consequence is a service crash.
The record
- CVE
- CVE-2022-4900
- Published
- Nov 2, 2023
- Updated
- Nov 3, 2025
- Vendor
- Red Hat
- Product
- Red Hat Enterprise Linux 8
- Classifications
- CWE-787, CWE-119, T1499.004
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 2, 2023CVE publishedPublication date reported by the CVE source.
- Nov 3, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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