Process crash via recursive DTD model construction
Published Feb 18, 2022 · Updated May 30, 2025
Stack exhaustion in Expat before 2.4.5 allows attackers to crash an XML-processing application via a deeply nested DTD element. The build_model function recursively calls build_node for each nested DTD child without imposing a depth limit, allowing parser-controlled nesting to consume the call stack. Exploitation requires an application to parse attacker-supplied XML containing a deeply nested DTD; the bounded consequence is a process crash and resulting service interruption.
Summary
What happened
Stack exhaustion in Expat before 2.4.5 allows attackers to crash an XML-processing application via a deeply nested DTD element. The build_model function recursively calls build_node for each nested DTD child without imposing a depth limit, allowing parser-controlled nesting to consume the call stack. Exploitation requires an application to parse attacker-supplied XML containing a deeply nested DTD; the bounded consequence is a process crash and resulting service interruption.
The record
- CVE
- CVE-2022-25313
- Published
- Feb 18, 2022
- Updated
- May 30, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-674, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 18, 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
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
- Upstream build_model stack-exhaustion proof of conceptproof of concept · unverified
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Technologies
Your stack
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Your stack
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