Service denial via recursive XML entity expansion
Published Mar 26, 2024 · Updated Aug 15, 2024
XML entity expansion in LangChain before 0.1.35 allows remote attackers to exhaust service CPU and memory through XMLOutputParser. The parser's parse, transform, and asynchronous transform paths feed untrusted XML to Python ElementTree parsers that permit recursive DTD entity expansion. Exploitation requires XMLOutputParser in a web-exposed application and malicious XML supplied directly or induced through an LLM, resulting in resource exhaustion and service interruption.
Summary
What happened
XML entity expansion in LangChain before 0.1.35 allows remote attackers to exhaust service CPU and memory through XMLOutputParser. The parser's parse, transform, and asynchronous transform paths feed untrusted XML to Python ElementTree parsers that permit recursive DTD entity expansion. Exploitation requires XMLOutputParser in a web-exposed application and malicious XML supplied directly or induced through an LLM, resulting in resource exhaustion and service interruption.
The record
- CVE
- CVE-2024-1455
- Published
- Mar 26, 2024
- Updated
- Aug 15, 2024
- Vendor
- LangChain
- Product
- LangChain
- Classifications
- CWE-776, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 26, 2024CVE publishedPublication date reported by the CVE source.
- Aug 15, 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=0 <0.1.35
- Affected versionversion=unspecified <0.1.35
What conditions does exploitation require?
What is affected?
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
- MALICIOUS_XML Billion Laughs regression payloadproof 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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