A buffer overflow in the fribidi_get_par_embedding_levels_ex() function in lib/fribidi-bidi.c of GNU FriBidi through 1.0.7 allows an attacker to cause a denial of service or possibly execute arbitrary code by delivering crafted text content to a user, when this content is then rendered by an application that uses FriBidi for text layout calculations. Examples include any GNOME or GTK+ based application that uses Pango for text layout, as this internally uses FriBidi for bidirectional text layout. For example, the attacker can construct a crafted text file to be opened in GEdit, or a crafted IRC message to be viewed in HexChat.
https://access.redhat.com/errata/RHSA-2019:4326
https://access.redhat.com/errata/RHSA-2019:4361
https://access.redhat.com/errata/RHSA-2020:0291
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=944327
https://github.com/fribidi/fribidi/commit/034c6e9a1d296286305f4cfd1e0072b879f52568
https://marc.info/?l=oss-security&m=157322128105807&w=2