CVE-2020-27771

Severity: low (CVSS 3.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2020-12-04 · updated 2026-06-17
Weakness: CWE-190

Description

In RestoreMSCWarning() of /coders/pdf.c there are several areas where calls to GetPixelIndex() could result in values outside the range of representable for the unsigned char type. The patch casts the return value of GetPixelIndex() to ssize_t type to avoid this bug. This undefined behavior could be triggered when ImageMagick processes a crafted pdf file. Red Hat Product Security marked this as Low severity because although it could potentially lead to an impact to application availability, no specific impact was demonstrated in this case. This flaw affects ImageMagick versions prior to 7.0.9-0.

Affected products

Debian Linux: 9.0
ImageMagick: before 6.9.10-69; from 7.0.0-0 before 7.0.9 — fixed in 6.9.10-69, 7.0.9
Red Hat Enterprise Linux: 5.0, 6.0, 7.0

How to fix

Upgrade to a fixed version: ImageMagick 6.9.10-69, 7.0.9. Check the vendor advisory for mitigations.

References

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