What’s Vulnerable › Vulnerabilities

CVE-2021-25832

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 12.6% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-03-01 · updated 2026-06-17
• Weakness: CWE-787

Description

A heap buffer overflow vulnerability inside of BMP image processing was found at [core] module of ONLYOFFICE DocumentServer v4.0.0-9-v6.0.0. Using this vulnerability, an attacker is able to gain remote code executions on DocumentServer.

Affected products

• ONLYOFFICE Document Server: from 4.0.0-9 through 6.0.0

References

• https://github.com/ONLYOFFICE/DocumentServer
• https://github.com/ONLYOFFICE/core
• https://github.com/ONLYOFFICE/core/blob/v6.0.1.15/ASCOfficePPTXFile/Editor/BinaryFileReaderWriter.cpp#L424
• https://github.com/ONLYOFFICE/core/blob/v6.0.1.15/ASCOfficePPTXFile/Editor/BinaryFileReaderWriter.cpp#L428
• https://github.com/ONLYOFFICE/core/blob/v6.0.1.15/DesktopEditor/cximage/CxImage/ximabmp.cpp#L354
• https://github.com/ONLYOFFICE/core/blob/v6.0.1.15/DesktopEditor/cximage/CxImage/ximabmp.cpp#L358
• https://github.com/merrychap/poc_exploits/tree/master/ONLYOFFICE/CVE-2021-25832
• https://github.com/ONLYOFFICE/DocumentServer
• https://github.com/ONLYOFFICE/core
• https://github.com/ONLYOFFICE/core/blob/v6.0.1.15/ASCOfficePPTXFile/Editor/BinaryFileReaderWriter.cpp#L424
• https://github.com/ONLYOFFICE/core/blob/v6.0.1.15/ASCOfficePPTXFile/Editor/BinaryFileReaderWriter.cpp#L428
• https://github.com/ONLYOFFICE/core/blob/v6.0.1.15/DesktopEditor/cximage/CxImage/ximabmp.cpp#L354

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