CVE-2022-29777Network attack vector

Remote code execution via negative font index

Published Jun 1, 2022 · Updated Aug 3, 2024

Heap buffer underflow in ONLYOFFICE Document Server 6.0.0 and earlier allows remote attackers to execute code through a crafted file. In Core 6.1.0.26 and earlier, CFontFileType1::Parse accepts a negative atoi result as an m_arrEncoding array index and writes before the allocated heap buffer. An unauthenticated network request must supply the malicious font data; successful exploitation overwrites a neighboring heap pointer, enabling code execution or a process crash.

CVSS severity9.8
Critical
EPSS probability6.91%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap buffer underflow in ONLYOFFICE Document Server 6.0.0 and earlier allows remote attackers to execute code through a crafted file. In Core 6.1.0.26 and earlier, CFontFileType1::Parse accepts a negative atoi result as an m_arrEncoding array index and writes before the allocated heap buffer. An unauthenticated network request must supply the malicious font data; successful exploitation overwrites a neighboring heap pointer, enabling code execution or a process crash.

The record

CVE
CVE-2022-29777
Published
Jun 1, 2022
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 1, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NVDAV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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