A heap-based buffer overflow in the sixel_encoder_output_without_macro function in encoder.c of Libsixel 1.8.4 allows attackers to cause a denial of service (DOS) via converting a crafted PNG file into Sixel format.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-21677
Reference (s):
- https://github.com/saitoha/libsixel/issues/123