From c36b95c57f85a34ad85ca2be34f62ff1100d52f1 Mon Sep 17 00:00:00 2001 From: Ahmet Furkan Kavraz <55850855+ahmetfurkankavraz@users.noreply.github.com> Date: Sat, 31 Jan 2026 21:23:41 +0100 Subject: [PATCH] Fix CVE-2025-15270: Heap buffer overflow in SFD kern class parsing (#5743) Fixes: CVE-2025-15270 | ZDI-25-1194 | ZDI-CAN-28563 Co-authored-by: Ahmet Furkan Kavraz CVE: CVE-2025-15270 Upstream-Status: Backport [https://github.com/fontforge/fontforge/commit/d01333a5bfa2ac4ed698c24b323d02107deacad7] Signed-off-by: Gyorgy Sarvari --- fontforge/sfd.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fontforge/sfd.c b/fontforge/sfd.c index 940627a3b..99d92b051 100644 --- a/fontforge/sfd.c +++ b/fontforge/sfd.c @@ -8276,6 +8276,10 @@ bool SFD_GetFontMetaData( FILE *sfd, for ( i=classstart; ifirst_cnt; ++i ) { if (kernclassversion < 3) { getint(sfd,&temp); + if (temp < 0) { + LogError(_("Corrupted SFD file: Invalid kern class name length %d. Aborting load."), temp); + return false; + } kc->firsts[i] = malloc(temp+1); kc->firsts[i][temp] = '\0'; nlgetc(sfd); /* skip space */ fread(kc->firsts[i],1,temp,sfd); @@ -8293,6 +8297,10 @@ bool SFD_GetFontMetaData( FILE *sfd, for ( i=1; isecond_cnt; ++i ) { if (kernclassversion < 3) { getint(sfd,&temp); + if (temp < 0) { + LogError(_("Corrupted SFD file: Invalid kern class name length %d. Aborting load."), temp); + return false; + } kc->seconds[i] = malloc(temp+1); kc->seconds[i][temp] = '\0'; nlgetc(sfd); /* skip space */ fread(kc->seconds[i],1,temp,sfd);