Vulnerability · Published Mar 1, 2021 · Assigned by mitre
CVE-2021-25831
Critical 9.8
In plain English
A critical-severity security flaw in the affected software. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 11.5% (higher than 96% of all known vulnerabilities).
Severity (CVSS NVD)9.8Critical
Exploit odds (30 days)11.5%top 4.0% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
A file extension handling issue was found in [core] module of ONLYOFFICE DocumentServer v4.0.0-9-v5.6.3. An attacker must request the conversion of the crafted file from PPTT into PPTX format. Using the chain of two other bugs related to improper string handling, a remote attacker can obtain remote code execution on DocumentServer.
Affected products (as reported)
References
- https://github.com/ONLYOFFICE/DocumentServer x_refsource_MISC
- https://github.com/ONLYOFFICE/core x_refsource_MISC
- https://github.com/ONLYOFFICE/core/blob/v5.6.4.13/ASCOfficePPTXFile/Editor/BinaryFileReaderWriter.cpp#L241 x_refsource_MISC
- https://github.com/ONLYOFFICE/core/blob/v5.6.4.13/ASCOfficePPTXFile/Editor/BinaryFileReaderWriter.cpp#L1918 x_refsource_MISC
- https://github.com/ONLYOFFICE/core/blob/v5.6.4.13/ASCOfficePPTXFile/PPTXFormat/Logic/Fills/BlipFill.cpp#L328 x_refsource_MISC
- https://github.com/merrychap/poc_exploits/tree/master/ONLYOFFICE/CVE-2021-25831 x_refsource_MISC