Arbitrary server-side requests via userinfo allowlist bypass
Published Jun 27, 2023 · Updated Feb 13, 2025
Server-side request forgery in PlantUML before 1.2023.9 allows remote attackers to request arbitrary URLs through crafted diagram input. SURL strips URL user information with a restrictive, unanchored regular expression before a prefix allowlist comparison, so crafted userinfo makes an allowed prefix resolve to an attacker-selected host. Exploitation requires a deployment that renders untrusted diagrams with URL access enabled; successful requests can reach network resources available to that process.
Summary
What happened
Server-side request forgery in PlantUML before 1.2023.9 allows remote attackers to request arbitrary URLs through crafted diagram input. SURL strips URL user information with a restrictive, unanchored regular expression before a prefix allowlist comparison, so crafted userinfo makes an allowed prefix resolve to an attacker-selected host. Exploitation requires a deployment that renders untrusted diagrams with URL access enabled; successful requests can reach network resources available to that process.
The record
- CVE
- CVE-2023-3432
- Published
- Jun 27, 2023
- Updated
- Feb 13, 2025
- Vendor
- PlantUML
- Product
- PlantUML
- Classifications
- CWE-918, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 27, 2023CVE publishedPublication date reported by the CVE source.
- Feb 13, 2025Record 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=unspecified <1.2023.9
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
- Crafted diagram userinfo-bypass PoCproof of concept · unverified
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Technologies
Your stack
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Your stack
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