Service hang via backtracking HTML-tag regex
Published Jun 6, 2023 · Updated Aug 2, 2024
Regular expression denial of service in RedCloth before 4.3.3 allows remote attackers to hang applications processing crafted input. The sanitize_html function matches attacker-controlled text against an HTML-tag regex whose optional and repeated tokens cause excessive backtracking. Exposure requires an application to pass remote input through sanitize_html; the resulting CPU exhaustion interrupts that application.
Summary
What happened
Regular expression denial of service in RedCloth before 4.3.3 allows remote attackers to hang applications processing crafted input. The sanitize_html function matches attacker-controlled text against an HTML-tag regex whose optional and repeated tokens cause excessive backtracking. Exposure requires an application to pass remote input through sanitize_html; the resulting CPU exhaustion interrupts that application.
The record
- CVE
- CVE-2023-31606
- Published
- Jun 6, 2023
- Updated
- Aug 2, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-1333, CAPEC-492, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 6, 2023CVE publishedPublication date reported by the CVE source.
- Aug 2, 2024Record 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.
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
- ReDOS possible in the sanitize_html functionproof of concept · unverified
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Technologies
Your stack
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Your stack
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