CVE-2020-21531Public exploit

Converter crash via off-by-one pattern index

Published Sep 16, 2021 · Updated Aug 4, 2024

Global buffer overflow in Xfig fig2dev 3.2.7b allows context-dependent attackers to crash the converter via a crafted Xfig file. The conv_pattern_index function in gencgm.c performs an off-by-one range check while converting Xfig input to CGM, allowing an index to overrun a global buffer. Execution requires a user or automated workflow to process the malicious file; the established consequence is a fig2dev crash, not data disclosure or modification.

CVSS severity5.5
Medium
EPSS probability1.05%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Global buffer overflow in Xfig fig2dev 3.2.7b allows context-dependent attackers to crash the converter via a crafted Xfig file. The conv_pattern_index function in gencgm.c performs an off-by-one range check while converting Xfig input to CGM, allowing an index to overrun a global buffer. Execution requires a user or automated workflow to process the malicious file; the established consequence is a fig2dev crash, not data disclosure or modification.

The record

CVE
CVE-2020-21531
Published
Sep 16, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 16, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:P
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

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.

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No observations available

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

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1204.002Malicious File

Public exploit references

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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