Vulnerability 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.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Onlyoffice | Document Server | >= 4.0.0-9, <= 5.6.3 |
References
- https://github.com/ONLYOFFICE/DocumentServerProduct
- https://github.com/ONLYOFFICE/coreProductVendor Advisory
- https://github.com/ONLYOFFICE/core/blob/v5.6.4.13/ASCOfficePPTXFile/Editor/BinarVendor Advisory
- https://github.com/ONLYOFFICE/core/blob/v5.6.4.13/ASCOfficePPTXFile/Editor/BinarVendor Advisory
- https://github.com/ONLYOFFICE/core/blob/v5.6.4.13/ASCOfficePPTXFile/PPTXFormat/LVendor Advisory
- https://github.com/merrychap/poc_exploits/tree/master/ONLYOFFICE/CVE-2021-25831ExploitVendor Advisory
- https://github.com/ONLYOFFICE/DocumentServerProduct
- https://github.com/ONLYOFFICE/coreProductVendor Advisory
- https://github.com/ONLYOFFICE/core/blob/v5.6.4.13/ASCOfficePPTXFile/Editor/BinarVendor Advisory
- https://github.com/ONLYOFFICE/core/blob/v5.6.4.13/ASCOfficePPTXFile/Editor/BinarVendor Advisory
- https://github.com/ONLYOFFICE/core/blob/v5.6.4.13/ASCOfficePPTXFile/PPTXFormat/LVendor Advisory
- https://github.com/merrychap/poc_exploits/tree/master/ONLYOFFICE/CVE-2021-25831ExploitVendor Advisory
FAQ
What is CVE-2021-25831?
CVE-2021-25831 is a vulnerability with a CVSS score of 9.8 (CRITICAL). 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 t...
How severe is CVE-2021-25831?
CVE-2021-25831 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2021-25831?
Check the references section above for vendor advisories and patch information. Affected products include: Onlyoffice Document Server.