-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 iDEFENSE Security Advisory 02.10.03: http://www.idefense.com/advisory/02.10.03.txt Buffer Overflow In NOD32 Antivirus Software for Unix February 10, 2003 I. BACKGROUND Eset Software's NOD32 Antivirus System is a cross-platform anti-virus application. The Linux, FreeBSD, OpenBSD and NetBSD versions are compiled from the same sources, which the vendor refers to as "nod32 for UNIX". More information is available at http://www.nod32.com/products/unix.htm . II. DESCRIPTION Local exploitation of a buffer overflow in NOD32 for UNIX could allow attackers to gain super-user (root) privileges. The overflow occurs when NOD32 parses a path with a name of length greater than 500 characters (/tmp/AAAAA....AAA). An attacker can overwrite the first three bytes of the eax and ecx registers, as can be seen from the following GDB output: ... Program received signal SIGSEGV, Segmentation fault. 0x4207fa78 in strcmp () from /lib/i686/libc.so.6 (gdb) bt #0 0x4207fa78 in strcmp () from /lib/i686/libc.so.6 #1 0x0804c2ba in scan_dir () #2 0x41414141 in ?? () Cannot access memory at address 0x41414141 (gdb) info registers eax 0x4141414c 1094795596 ecx 0x4141414c 1094795596 ... III. ANALYSIS Exploitation allows local code execution with the privileges of the user who spawned NOD32. This is possible by creating an exploit path and then socially engineering a target user into scanning over the exploit path using NOD32. If the attacker has write permissions to a directory that is routinely scanned with NOD32 (such as /tmp), he or she can gain the privileges of the scanning user (usually root). Proof of concept exploit code has been written for the FreeBSD 4.7 platform. The following is a sample exploit run that should set up shell code in an environment variable and spawn a shell under the privileges of the user executing NOD32: $ perl eggnod.pl $ mkdir -p /tmp/`perl -e 'print "A" x 255'`/`perl -e 'print "B" x 240 . "\xfc\xbf\xbf"'` $ nod32 /tmp IV. DETECTION NOD32 Antivirus System for Unix version 1.012 and below is vulnerable. V. VENDOR FIX The latest version 1.013 fixes the issue and can be downloaded from http://www.nod32.com VI. CVE INFORMATION The Mitre Corp.'s Common Vulnerabilities and Exposures (CVE) Project assigned the identification number CAN-2003-0062 to this issue. VII. DISCLOSURE TIMELINE 12/03/2003 Issue disclosed to iDEFENSE 01/28/2003 Eset Software notified (webmasterat_private) 01/28/2003 iDEFENSE clients notified 02/03/2003 Response received from Palo Luka (lukaat_private) 02/10/2003 Coordinated Public Disclosure VIII. CREDIT Knud Erik Højgaard (knudat_private) discovered this vulnerability. Get paid for security research http://www.idefense.com/contributor.html Subscribe to iDEFENSE Advisories: send email to listservat_private, subject line: "subscribe" About iDEFENSE: iDEFENSE is a global security intelligence company that proactively monitors sources throughout the world — from technical vulnerabilities and hacker profiling to the global spread of viruses and other malicious code. Our security intelligence services provide decision-makers, frontline security professionals and network administrators with timely access to actionable intelligence and decision support on cyber-related threats. For more information, visit http://www.idefense.com . -----BEGIN PGP SIGNATURE----- Version: PGP 8.0 iQA/AwUBPkgBffrkky7kqW5PEQIq/gCeMsnn0gKxpM25GI/QO673cEV7iAsAn15C d5dxClPtqnk53TP0W2dmIJKS =Smty -----END PGP SIGNATURE-----
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