Miscalculations in the safe_fprintf() function meant that the buffer allocated for decoding could be overflowed by crafted Unicode filenames. Disclosed on oss-security: http://seclists.org/oss-sec/2016/q3/516 Upstream issue: https://github.com/libarchive/libarchive/issues/767 Upstream fix: https://github.com/libarchive/libarchive/commit/e37b620f
This only affects the bsdtar utility, libraries and applications linked against libarchive are not affected by this flaw. Compiling with -fstack-protector-strong (as is the case in RHEL & Fedora) mitigates any code execution vector here. In any case, the overflowed bytes are limited to ASCII octal escapes so even without these protections an attacker would need to be incredibly lucky to achieve more than a crash.
Created libarchive tracking bugs for this issue: Affects: fedora-all [bug 1378666]
Statement: Red Hat Product Security has rated this issue as having Low security impact. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.
*** Bug 1385659 has been marked as a duplicate of this bug. ***