Document structure corruption via malformed XML round-trip
Published Apr 21, 2021 · Updated Aug 3, 2024
XML round-trip corruption in REXML 3.2.4 and earlier allows attackers to alter a document's structure via crafted XML. The parser accepts malformed element boundaries and the notation serializer selects unsafe quote delimiters, so parse-and-serialize output can expose injected markup as elements. Exploitation requires an application to parse attacker-controlled XML, serialize it, and then trust the changed structure; the resulting security impact depends on that application's use of the output.
Summary
What happened
XML round-trip corruption in REXML 3.2.4 and earlier allows attackers to alter a document's structure via crafted XML. The parser accepts malformed element boundaries and the notation serializer selects unsafe quote delimiters, so parse-and-serialize output can expose injected markup as elements. Exploitation requires an application to parse attacker-controlled XML, serialize it, and then trust the changed structure; the resulting security impact depends on that application's use of the output.
The record
- CVE
- CVE-2021-28965
- Published
- Apr 21, 2021
- Updated
- Aug 3, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- Unavailable
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 21, 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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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.
Weakness, pattern, technique
No sourced classifications are available.
Public exploit references
- REXML XML round-trip demonstrationproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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