Unauthenticated memory corruption via malformed multipart body
Published Dec 20, 2021 · Updated Aug 4, 2024
Buffer overflow in mod_lua in Apache HTTP Server 2.4.51 and earlier allows remote attackers to corrupt memory via multipart requests. In r:parsebody(), the multipart parser subtracts eight from a too-short delimiter span without checking its length, underflowing vlen before allocation and memcpy. A reachable Lua script must call r:parsebody(); Apache reported no known exploit, so demonstrated impact beyond memory corruption is unavailable.
Summary
What happened
Buffer overflow in mod_lua in Apache HTTP Server 2.4.51 and earlier allows remote attackers to corrupt memory via multipart requests. In r:parsebody(), the multipart parser subtracts eight from a too-short delimiter span without checking its length, underflowing vlen before allocation and memcpy. A reachable Lua script must call r:parsebody(); Apache reported no known exploit, so demonstrated impact beyond memory corruption is unavailable.
The record
- CVE
- CVE-2021-44790
- Published
- Dec 20, 2021
- Updated
- Aug 4, 2024
- Vendor
- The Apache Software Foundation
- Product
- Apache HTTP Server
- Classifications
- CWE-787, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 20, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=Apache HTTP Server 2.4 <=2.4.51
What conditions does exploitation require?
What is affected?
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.
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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