CVE-2021-25829
An improper binary stream data handling issue was found in the [core] module of ONLYOFFICE...
An improper binary stream data handling issue was found in the [core] module of ONLYOFFICE DocumentServer v4.0.0-9-v5.6.3. Using this bug, an attacker is able to produce a denial of service attack that can eventually shut down the target server.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
An improper binary stream data handling issue was found in the [core] module of ONLYOFFICE DocumentServer v4.0.0-9-v5.6.3. Using this bug, an attacker is able to produce a denial of service attack that can eventually shut down the target server.
- Record
CVE-2021-25829- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 7.8 High
AV:N/AC:L/Au:N/C:N/I:N/A:C - Updated
- 2026-11-02
CVE List No score
An improper binary stream data handling issue was found in the [core] module of ONLYOFFICE DocumentServer v4.0.0-9-v5.6.3. Using this bug, an attacker is able to produce a denial of service attack that can eventually shut down the target server.
- Record
CVE-2021-25829- Updated
- 2026-11-02
EUVDEUVD-2021-12712 No score
An improper binary stream data handling issue was found in the [core] module of ONLYOFFICE DocumentServer v4.0.0-9-v5.6.3. Using this bug, an attacker is able to produce a denial of service attack that can eventually shut down the target server.
- Record
EUVD-2021-12712- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-jmxf-5qxj-85w9 No score
An improper binary stream data handling issue was found in the [core] module of ONLYOFFICE...
An improper binary stream data handling issue was found in the [core] module of ONLYOFFICE DocumentServer v4.0.0-9-v5.6.3. Using this bug, an attacker is able to produce a denial of service attack that can eventually shut down the target server.
- Record
GHSA-jmxf-5qxj-85w9- Updated
- 2026-11-02
OSV
An improper binary stream data handling issue was found in the [core] module of ONLYOFFICE DocumentServer v4.0.0-9-v5.6.3. Using this bug, an attacker is able to produce a denial of service attack that can eventually shut down the target server.
- Record
CVE-2021-25829- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-25829 is a high vulnerability (CVSS 7.5) in Onlyoffice Document Server, published March 1, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 7.45%, the 94th percentile. No source names a fixed version.
References
github.com/ONLYOFFICE/DocumentServer
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nvd.nist.gov/vuln/detail/CVE-2021-25829