CVE-2021-25831

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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTNIST
9.8 CRITICAL
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
mitreCNA
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CVEADP
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Base Score
CVSS 3.x
EPSS Score
Percentile: 87%
VendorProductVersion
onlyofficedocument_server
4.0.0-9 ≤
𝑥
≤ 5.6.3
𝑥
= Vulnerable software versions
References
https://github.com/ONLYOFFICE/DocumentServer
https://github.com/ONLYOFFICE/core
https://github.com/ONLYOFFICE/core/blob/v5.6.4.13/ASCOfficePPTXFile/Editor/BinaryFileReaderWriter.cpp#L1918
https://github.com/ONLYOFFICE/core/blob/v5.6.4.13/ASCOfficePPTXFile/Editor/BinaryFileReaderWriter.cpp#L241
https://github.com/ONLYOFFICE/core/blob/v5.6.4.13/ASCOfficePPTXFile/PPTXFormat/Logic/Fills/BlipFill.cpp#L328
https://github.com/merrychap/poc_exploits/tree/master/ONLYOFFICE/CVE-2021-25831
https://github.com/ONLYOFFICE/DocumentServer
https://github.com/ONLYOFFICE/core
https://github.com/ONLYOFFICE/core/blob/v5.6.4.13/ASCOfficePPTXFile/Editor/BinaryFileReaderWriter.cpp#L1918
https://github.com/ONLYOFFICE/core/blob/v5.6.4.13/ASCOfficePPTXFile/Editor/BinaryFileReaderWriter.cpp#L241
https://github.com/ONLYOFFICE/core/blob/v5.6.4.13/ASCOfficePPTXFile/PPTXFormat/Logic/Fills/BlipFill.cpp#L328
https://github.com/merrychap/poc_exploits/tree/master/ONLYOFFICE/CVE-2021-25831