From 30cd56ac389fbab521c52669a3bd25041d4e1df1 Mon Sep 17 00:00:00 2001 From: Jon Trulson Date: Mon, 6 May 2019 17:55:49 -0600 Subject: [PATCH] dtprintinfo: Fix a potential exploitable buffer overrun This fixes a potentially exploitable buffer overrun in dtprintinfo. This was brought to my attention based on a 0day exploit released for Solaris CDE. The exploit code does not work (or build) on linux, and the overrun is in the heap rather than the stack as on Solaris, but it's easy to see how this could be exploited. The following is the content of the advisory: 8<----------------------------------------------------------- @Mediaservice.net (Cybaze Group) Security Advisory #2019-01 (2019-05-07) Title: Local privilege escalation via CDE dtprintinfo Application: Common Desktop Environment 2.3.0 and earlier Platforms: Oracle Solaris 10 1/13 (Update 11) and earlier Description: A local attacker can gain root privileges by exploiting a buffer overflow in CDE dtprintinfo Author: Marco Ivaldi Contributor: Dave Aitel (original discovery) Vendor Status: notified on 2019-05-05 notified on 2019-05-05 CVE: The Common Vulnerabilities and Exposures project has not assigned a name to this issue yet References: https://lab.mediaservice.net/advisory/2019-01-cde-dtprintinfo.txt https://github.com/0xdea/raptor_infiltrate19 https://sourceforge.net/p/cdesktopenv/wiki/Home/ https://www.oracle.com/technetwork/server-storage/solaris10/ https://www.mediaservice.net/ https://infiltratecon.com/ 1. Abstract. A buffer overflow in the DtPrinterAction::PrintActionExists() function in the Common Desktop Environment 2.3.0 and earlier, as used in Oracle Solaris 10 1/13 (Update 11) and earlier, allows local users to gain root privileges via a long printer name passed to dtprintinfo by a malicious lpstat program. This is a 0day vulnerability demonstrated at #INFILTRATE19 on May 2nd, 2019 in the talk "A bug's life: story of a Solaris 0day". 2. Example Attack Session. bash-3.2$ cat /etc/release Oracle Solaris 10 1/13 s10x_u11wos_24a X86 Copyright (c) 1983, 2013, Oracle and/or its affiliates. All rights reserved. Assembled 17 January 2013 bash-3.2$ uname -a SunOS nostalgia 5.10 Generic_147148-26 i86pc i386 i86pc bash-3.2$ id uid=54322(raptor) gid=1(other) bash-3.2$ gcc raptor_dtprintname_intel.c -o raptor_dtprintname_intel -Wall bash-3.2$ ./raptor_dtprintname_intel 192.168.1.1:0 raptor_dtprintname_intel.c - dtprintinfo 0day, Solaris/Intel Copyright (c) 2004-2019 Marco Ivaldi Using SI_PLATFORM : i86pc (5.10) Using stack base : 0x8047fff Using rwx_mem address : 0xfeffa004 Using sc address : 0x8047f60 Using strcpy() address : 0xfefe26a0 lpstat called with -v lpstat called with -v lpstat called with -d uid=0(root) gid=1(other) 3. Affected Platforms. All platforms shipping the Common Desktop Environment are potentially affected. This includes: * Oracle Solaris 10 1/13 (Update 11) and earlier [default installation] According to the CDE Wiki, the following platforms are officially supported: * All Official Ubuntu variants 12.04 - 18.04 * Debian 6, 7, 8, 9 * Fedora 17 at least * Archlinux * Red Hat * Slackware 14.0 * OpenBSD * NetBSD * FreeBSD 9.2, 10.x, 11.x * openSUSE Tumbleweed (gcc7) * openSUSE Leap 4.2 (gcc4) * SUSE 12 SP3 (gcc4) * Solaris, OpenIndiana 4. Fix. The upstream CDE maintainers have issued a patch for this vulnerability. Oracle is investigating the issue via tracking# S1153109 and is expected to release a fix for all affected-supported versions of Solaris via their quarterly Critical Patch Update (CPU) program. As a temporary workaround, it is possible to remove the setuid bit from the dtprintinfo executable as follows: bash-3.2# chmod -s /usr/dt/bin/dtprintinfo 5. Proof of Concept. A working exploit for Oracle Solaris 10 1/13 (Update 11) Intel has been developed as a proof of concept. Exploits for other Solaris versions and for the SPARC architecture are also available. All exploits can be downloaded at: https://github.com/0xdea/raptor_infiltrate19/ https://github.com/0xdea/exploits/ 8<----------------------------------------------------------- --- cde/programs/dtprintinfo/UI/DtPrinterIcon.C | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/cde/programs/dtprintinfo/UI/DtPrinterIcon.C b/cde/programs/dtprintinfo/UI/DtPrinterIcon.C index 51f79bef..69a65960 100644 --- a/cde/programs/dtprintinfo/UI/DtPrinterIcon.C +++ b/cde/programs/dtprintinfo/UI/DtPrinterIcon.C @@ -740,8 +740,8 @@ void DtPrinterIcon::OpenCloseCB(void *data) boolean DtPrinterIcon::PrintActionExists() { boolean b; - char *buf = new char[60]; - sprintf(buf, "%s_Print", queue->Name()); + char *buf = new char[256]; + snprintf(buf, 256, "%s_Print", queue->Name()); b = (DtActionExists(buf) ? true : false); delete [] buf; return b; -- 2.25.1