Vulnerabilities > CVE-2020-27771 - Integer Overflow or Wraparound vulnerability in multiple products
Summary
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.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Forced Integer Overflow This attack forces an integer variable to go out of range. The integer variable is often used as an offset such as size of memory allocation or similarly. The attacker would typically control the value of such variable and try to get it out of range. For instance the integer in question is incremented past the maximum possible value, it may wrap to become a very small, or negative number, therefore providing a very incorrect value which can lead to unexpected behavior. At worst the attacker can execute arbitrary code.
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1898290
- https://bugzilla.redhat.com/show_bug.cgi?id=1898290
- https://lists.debian.org/debian-lts-announce/2021/03/msg00030.html
- https://lists.debian.org/debian-lts-announce/2021/03/msg00030.html
- https://lists.debian.org/debian-lts-announce/2023/03/msg00008.html
- https://lists.debian.org/debian-lts-announce/2023/03/msg00008.html