CVE-2019-12331
moderate-risk
Published 2019-11-07
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.
Do I need to act?
-
0.12% chance of exploitation
EPSS score — low exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
8
CVSS 8.8/10
High
NETWORK
/ LOW complexity
Affected Products (1)
Affected Vendors
References (4)
Third Party Advisory
https://github.com/PHPOffice/PhpSpreadsheet/blob/master/CHANGELOG.md#180---2019-...
Third Party Advisory
https://github.com/PHPOffice/PhpSpreadsheet/blob/master/CHANGELOG.md#180---2019-...
36
/ 100
moderate-risk
Severity
30/34 · Critical
Exploitability
1/34 · Minimal
Exposure
5/34 · Minimal