Integer overflow in Imagemagick

CVE-2020-27771

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.

Vulnerability class: Integer Overflow

EPSS: 0.012 (63.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 3.3 (Low). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2020-27771?
CVE-2020-27771 is a low-severity vulnerability in Imagemagick, classified under Integer Overflow or Wraparound. CVSS score: 3.3/10. Published 2020-12-04.
How severe is CVE-2020-27771?
Low severity. CVSS v3 base score is 3.3 out of 10.
Is CVE-2020-27771 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.