PhpSpreadsheet: XmlScanner Bypass via Double-Encoded unentity() TOCTOU Allows XXE and Denial of Service
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 3.10.8, 5.10.0
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: yes
- Technical impact: partial
Summary
PhpSpreadsheet, a PHP library for reading and writing spreadsheet files, is affected when it processes SpreadsheetML (XML-based) spreadsheet files from untrusted sources. An attacker can craft such a file to bypass the library's XML safety checks, which can lead to denial of service through entity expansion, and in some PHP configurations, local file disclosure or server-side request forgery.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original description
PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. From 3.3.0 until 3.10.8 and 5.10.0, Reader\Xml passes stored SpreadsheetML XML through XmlScanner::scan in Xml::canRead and Xml::trySimpleXMLLoadStringPrivate, while Xml::unentity decodes numeric entities only after each DOCTYPE pattern check. A double-encoded less-than character is reduced by the first callback to another encoded character and by the second callback to a literal less-than sign, so SimpleXML receives an unchecked DOCTYPE and entity declaration. Processing attacker-controlled SpreadsheetML XML can cause entity-expansion denial of service and can permit local file access or SSRF on PHP before 8.0 or when LIBXML_NOENT is enabled. This issue is fixed in versions 3.10.8 and 5.10.0.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- PHPOffice PhpSpreadsheet
From 3.3.0 · fixed in 3.10.8; From 4.0.0 · fixed in 5.10.0
- phpoffice/phpspreadsheetPackagist
From 4.0.0 · fixed in 5.10.0
- phpoffice/phpspreadsheetPackagist
From 3.3.0 · fixed in 3.10.8