Red Hat Bugzilla – Bug 435420
CVE-2008-1078 am-utils: insecure usage of temporary files
Last modified: 2010-12-23 11:33:05 EST
Common Vulnerabilities and Exposures assigned an identifier CVE-2008-1078 to the following vulnerability:
expn in the am-utils and net-fs packages for Gentoo rPath Linux, and
other distributions, allows local users to overwrite arbitrary files
via a symlink attack on the expn[PID] temporary file. NOTE: this is
the same issue as CVE-2003-0308.1.
--- expn.orig 2008-02-14 15:34:05.083376000 +0000
+++ expn 2008-02-14 15:37:11.380887000 +0000
@@ -9,6 +9,7 @@
# hardcoded constants, should work fine for BSD-based systems
#require 'sys/socket.ph'; # perl 4
use Socket; # perl 5
$AF_INET = &AF_INET;
$SOCK_STREAM = &SOCK_STREAM;
@@ -1009,7 +1010,7 @@
$0 = "$av0 - nslookup of $server";
- open(T,">/tmp/expn$$") || die "open > /tmp/expn$$: $!\n";
+ sysopen(T,"/tmp/expn$$", O_EXCL | O_CREAT) || die "open > /tmp/expn$$:
print T "set querytype=MX\n";
print T "$server\n";
I'm going to wontfix this flaw. The time and effort required to fix it is far
greater than the possible damage is can do.
After investigating the source for all of Red Hat Enterprise Linux, it was noted
that nothing shipped ever runs this tool. This means that the only possible way
this can be exploited is if an admin runs it manually, or via a custom script.
If you feel this analysis if flawed, please feel free to add a comment.
No package in Fedora 8 depends on am-utils or /usr/bin/expn.
I've created tracking bug for Fedora rawhide, so that this issue gets fixed for
future versions of Fedora and Red Hat Enterprise Linux.
am-utils-6.1.5-8.1.fc9 has been submitted as an update for Fedora 9.
am-utils-6.1.5-8.1.fc9 has been pushed to the Fedora 9 stable repository. If problems still persist, please make note of it in this bug report.