libelf: Fix dir traversal vuln in ar extraction. read_long_names terminates names at the first '/' found but then skips one character without checking (it's supposed to be '\n'). Hence the next name could start with any character including '/'. This leads to a directory traversal vulnerability at the time the contents of the archive is extracted. The danger is mitigated by the fact that only one '/' is possible in a resulting filename and only in the leading position. Hence only files in the root directory can be written via this vuln and only when ar is executed as root. The fix for the vuln is to not skip any characters while looking for '/'. Upstream commit: https://git.fedorahosted.org/cgit/elfutils.git/commit/ ?id=147018e729e7c22eeabf15b82d26e4bf68a0d18e Fixes CVE-2014-9447 Upstream-Status: Backport Signed-off-by: Alexander Cherepanov Signed-off-by: Sona Sarmadi --- diff -ruN a/libelf/ChangeLog b/libelf/ChangeLog --- a/libelf/ChangeLog 2015-03-03 12:39:39.255277970 +0100 +++ b/libelf/ChangeLog 2015-03-03 12:43:44.700870042 +0100 @@ -1,3 +1,8 @@ +2014-12-28 Alexander Cherepanov + + * elf_begin.c (read_long_names): Don't miss '/' right after + another '/'. Fixes a dir traversal vuln in ar extraction. + 2012-08-16 Roland McGrath * elf.h: Update from glibc. diff -ruN a/libelf/elf_begin.c b/libelf/elf_begin.c --- a/libelf/elf_begin.c 2015-03-03 12:39:39.835253375 +0100 +++ b/libelf/elf_begin.c 2015-03-03 12:41:30.906543370 +0100 @@ -744,10 +744,7 @@ break; /* NUL-terminate the string. */ - *runp = '\0'; - - /* Skip the NUL byte and the \012. */ - runp += 2; + *runp++ = '\0'; /* A sanity check. Somebody might have generated invalid archive. */