CVE-2020-25690Network attack vector

Code execution via undersized LayerCount heap allocation

Published Feb 23, 2021 · Updated Aug 4, 2024

Out-of-bounds write in FontForge before 20200314 allows remote attackers to execute arbitrary code via a crafted SFD file. SFD_GetFontMetaData accepts a LayerCount value but reallocates the layer array using the stale count, leaving the heap allocation smaller than the recorded layer count. A user must open or otherwise process the attacker-supplied font; exploitation can crash FontForge or run code in its process context.

CVSS severity8.8
High
EPSS probability1.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in FontForge before 20200314 allows remote attackers to execute arbitrary code via a crafted SFD file. SFD_GetFontMetaData accepts a LayerCount value but reallocates the layer array using the stale count, leaving the heap allocation smaller than the recorded layer count. A user must open or otherwise process the attacker-supplied font; exploitation can crash FontForge or run code in its process context.

The record

CVE
CVE-2020-25690
Published
Feb 23, 2021
Updated
Aug 4, 2024
Vendor
FontForge
Product
FontForge
Classifications
CWE-119, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 23, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=fontforge before 20200314

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FontForge · FontForgeversion=fontforge before 20200314

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NIST NVDAV:N/AC:M/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-119Improper Restriction of Operations within the Bounds of a Memory Buffer
T1203Exploitation for Client Execution

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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