High severity · published Nov 7, 2019
CVE-2019-12331
PHPOffice PhpSpreadsheet before 1.8.0 has an XXE issue
8.8
CVSS
1.4%
EPSS
No
On KEV
Description
PHPOffice PhpSpreadsheet before 1.8.0 has an XXE issue. The XmlScanner decodes the sheet1.xml from an .xlsx to utf-8 if something else than UTF-8 is declared in the header. This was a security measurement to prevent CVE-2018-19277 but the fix is not sufficient. By double-encoding the the xml payload to utf-7 it is possible to bypass the check for the string ‚<!ENTITY‘ and thus allowing for an xml external entity processing (XXE) attack.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.4% · higher than 71% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PH
Phpspreadsheet · Phpoffice
before 1.8.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-12331
CVE.org
https://www.cve.org/CVERecord?id=CVE-2019-12331
Third Party Advisory
https://github.com/PHPOffice/PhpSpreadsheet/blob/master/CHANGELOG.md#180---2019-07-01
Exploit
https://herolab.usd.de/security-advisories/usd-2019-0046/
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