Data disclosure via UCS-4 XmlScanner regex bypass
Published Nov 18, 2024 · Updated Nov 18, 2024
XXE injection in PHPOffice PhpSpreadsheet affected releases allows remote attackers to trigger outbound requests through crafted XLSX files. XmlScanner scan trusts findCharSet regular expressions that miss null-byte-padded declarations in UCS-4, while the XML parser still guesses the encoding and resolves the external entity. Exploitation requires an embedding application to process an attacker-supplied XLSX file and exposes data reachable through external-entity resolution.
Summary
What happened
XXE injection in PHPOffice PhpSpreadsheet affected releases allows remote attackers to trigger outbound requests through crafted XLSX files. XmlScanner scan trusts findCharSet regular expressions that miss null-byte-padded declarations in UCS-4, while the XML parser still guesses the encoding and resolves the external entity. Exploitation requires an embedding application to process an attacker-supplied XLSX file and exposes data reachable through external-entity resolution.
The record
- CVE
- CVE-2024-47873
- Published
- Nov 18, 2024
- Updated
- Nov 18, 2024
- Vendor
- PHPOffice
- Product
- PhpSpreadsheet
- Classifications
- CWE-611
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 18, 2024CVE publishedPublication date reported by the CVE source.
- Nov 18, 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 <1.29.4
- Affected versionversion=< 1.29.4
- Affected versionversion=>= 2.0.0, < 2.1.3
- Affected versionversion=2.0.0 <2.1.3
- Affected versionversion=>= 2.2.0, < 2.3.2
- Affected versionversion=2.2.0 <2.3.2
- Affected versionversion=>= 3.3.0, < 3.4.0
- Affected versionversion=3.3.0 <3.4.0
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
- Upstream UCS-4 XXE proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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