Server crash via unchecked redirect URI concatenation
Published Aug 29, 2025 · Updated Aug 29, 2025
Heap buffer overflow in CivetWeb 1.14 through 1.16 allows remote attackers to crash the server via a crafted HTTP request. The handle_request function builds a directory-redirect URI in a fixed-size buffer, then uses unchecked strcat calls to append a slash, question mark, and attacker-controlled query string. Unauthenticated network access is sufficient; the public artifact demonstrates a crash, while code execution is reported but not demonstrated.
Summary
What happened
Heap buffer overflow in CivetWeb 1.14 through 1.16 allows remote attackers to crash the server via a crafted HTTP request. The handle_request function builds a directory-redirect URI in a fixed-size buffer, then uses unchecked strcat calls to append a slash, question mark, and attacker-controlled query string. Unauthenticated network access is sufficient; the public artifact demonstrates a crash, while code execution is reported but not demonstrated.
The record
- CVE
- CVE-2025-55763
- Published
- Aug 29, 2025
- Updated
- Aug 29, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-121, T1190, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 29, 2025CVE publishedPublication date reported by the CVE source.
- Aug 29, 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?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
- CivetWeb heap-overflow crash requestproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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