Process crash via premature shared DTD destruction
Published Oct 24, 2022 · Updated May 30, 2025
Use-after-free in libexpat 2.4.9 and earlier allows attackers to crash an XML-processing application during external entity parsing. When parserInit cannot allocate the protocol encoding name, parserCreate calls XML_ParserFree before m_isParamEntity protects the DTD shared with the root parser. This narrow gate requires external parameter-entity parsing and exhaustion of a small encoding-name allocation; reuse of the freed DTD interrupts the hosting process.
Summary
What happened
Use-after-free in libexpat 2.4.9 and earlier allows attackers to crash an XML-processing application during external entity parsing. When parserInit cannot allocate the protocol encoding name, parserCreate calls XML_ParserFree before m_isParamEntity protects the DTD shared with the root parser. This narrow gate requires external parameter-entity parsing and exhaustion of a small encoding-name allocation; reuse of the freed DTD interrupts the hosting process.
The record
- CVE
- CVE-2022-43680
- Published
- Oct 24, 2022
- Updated
- May 30, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-416, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 24, 2022CVE publishedPublication date reported by the CVE source.
- May 30, 2025Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
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Published CVSS scores
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Attacks
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Public exploit references
- Upstream allocation-failure reproducer testproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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