Denial of service via URL regex backtracking
Published Jan 13, 2021 · Updated Aug 3, 2024
Regular expression denial of service in jQuery Validation Plugin before 1.19.3 allows attackers to stall URL validation with crafted input. The url method in src/core.js applies an ambiguous URL regular expression whose overlapping repetitions cause exponential backtracking on malicious nonmatching strings. A reachable URL field accepting attacker-controlled values is required, and malicious nonmatching input consumes CPU until the affected execution context hangs.
Summary
What happened
Regular expression denial of service in jQuery Validation Plugin before 1.19.3 allows attackers to stall URL validation with crafted input. The url method in src/core.js applies an ambiguous URL regular expression whose overlapping repetitions cause exponential backtracking on malicious nonmatching strings. A reachable URL field accepting attacker-controlled values is required, and malicious nonmatching input consumes CPU until the affected execution context hangs.
The record
- CVE
- CVE-2021-21252
- Published
- Jan 13, 2021
- Updated
- Aug 3, 2024
- Vendor
- jQuery Validation
- Product
- jQuery Validation Plugin
- Classifications
- CWE-400, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 13, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 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=< 1.19.3
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.
Weakness, pattern, technique
Public exploit references
- GitHub Security Lab URL-validation proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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