Application crash via unbounded recursive HTML parsing
Published Jun 14, 2023 · Updated Jan 3, 2025
Denial of service in JTidy through r938 allows remote attackers to crash parsers that process deeply nested untrusted HTML. ParserImpl.ParseBlock recursively invokes parseTag for nested block elements without enforcing a depth limit, exhausting the JVM stack. Exploitation requires an application to pass attacker-controlled HTML to the parser; the resulting StackOverflowError terminates the parsing thread and can interrupt the hosting service.
Summary
What happened
Denial of service in JTidy through r938 allows remote attackers to crash parsers that process deeply nested untrusted HTML. ParserImpl.ParseBlock recursively invokes parseTag for nested block elements without enforcing a depth limit, exhausting the JVM stack. Exploitation requires an application to pass attacker-controlled HTML to the parser; the resulting StackOverflowError terminates the parsing thread and can interrupt the hosting service.
The record
- CVE
- CVE-2023-34623
- Published
- Jun 14, 2023
- Updated
- Jan 3, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-787, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 14, 2023CVE publishedPublication date reported by the CVE source.
- Jan 3, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
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
- Deeply nested HTML denial-of-service proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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