Package: gifsicle Version: 1.90-1 Severity: normal Dear Maintainer,
Running 'gifdiff' with the attached file raises a NULL pointer dereference, which may allow a denial-of-service attack of a malicious attacker. I expected the program to terminate without segfault, but the program crashes as follow. ---------------------------- (gdb) r poc poc Starting program: /usr/bin/gifdiff poc poc [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". gifdiff: While reading ‘poc’ frame #0: gifdiff: error: unknown block type 0 at file offset 13 gifdiff: While reading ‘poc’ frame #0: gifdiff: error: unknown block type 0 at file offset 13 Program received signal SIGSEGV, Segmentation fault. 0x000055555555ce38 in ?? () (gdb) x/i $rip => 0x55555555ce38: mov (%rdx,%rax,8),%rbx (gdb) i r rdx rdx 0x0 0 (gdb) i r rax rax 0x0 0 ----------------------------- The bug was found with a fuzzer developed by 'SoftSec' group at KAIST. -- System Information: Debian Release: 9.2 APT prefers stable-updates APT policy: (500, 'stable-updates'), (500, 'testing'), (500, 'stable') Architecture: amd64 (x86_64) Kernel: Linux 4.9.0-3-amd64 (SMP w/1 CPU core) Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages gifsicle depends on: ii libc6 2.24-11+deb9u1 ii libx11-6 2:1.6.4-3 gifsicle recommends no packages. gifsicle suggests no packages. -- no debconf information
GIF
