@RISK is the SANS community's consensus bulletin summarizing the most important vulnerabilities and exploits identified during the past week and providing guidance on appropriate actions to protect your systems (PART I). It also includes a comprehensive list of all new vulnerabilities discovered in the past week (PART II).
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Part I is compiled by Rohit Dhamankar (rohitd_at_tippingpoint.com) at TippingPoint, a division of 3Com, as a by-product of that company's continuous effort to ensure that its intrusion prevention products effectively block exploits using known vulnerabilities. TippingPoint's analysis is complemented by input from a council of security managers from twelve large organizations who confidentially share with SANS the specific actions they have taken to protect their systems. A detailed description of the process may be found at http://www.sans.org/newsletters/cva/#process
Description: Land attack, a denial-of service attack known since 1997, can be launched by directing IP packets with same source and destination IP addresses at the target machine. Windows XP (specifically SP2) and Windows 2003 server are reportedly vulnerable to this attack. By continuously sending a stream of malformed TCP "SYN" packets to the open ports on a Windows XP/2003 system, it is possible to cause a significant performance degradation (in some configurations 100% CPU utilization); there by, rendering the system unusable. The attack can be launched via packet crafting tools like hping. SANS Handler's diary shows the command line options that can be used with hping tool to launch this attack.
Status: Microsoft has not confirmed. A workaround for Windows 2003, which reportedly works, is to harden TCP/IP stack as described in the Microsoft KB324270. Appropriate ingress/egress filtering would also defend against this attack. Another alternative is to use firewalls, router ACLs and/or intrusion prevention systems to block such attacks.
Council Site Actions: Most of the council sites responded that they have mitigating controls in place such as firewall ACLs that block the malicious traffic from reaching their internal systems. They are all waiting on response from the vendor. Several mentioned they would install any future patches during a regular system update process.
Description: Sentinel LM is a software based license management application that supports multiple pre-built licensing models such as evaluation, pay-per-use, site license etc. The license manager, when installed on Windows, runs a service "LservNT" that listens on port 5093/udp. This service is vulnerable to a buffer overflow that can be triggered by 3000 bytes of data. The flaw can be exploited to execute arbitrary code with "SYSTEM" privileges. The License Manager also runs on other platforms like Mac OS, Solaris and Linux. It is not clear if these platforms are vulnerable as well.
Status: Vendor confirmed, upgrade to version 8.0 for any products using Sentinel LM. A workaround is to block port 5093/udp at the network perimeter.
Council Site Actions: The affected software is not in production or widespread use, or is not officially supported at any of the council sites. They reported that no action was necessary.
Description: Ethereal is a popular open source network sniffer and protocol analyzer for UNIX and Windows platforms. The software contains a stack-based buffer overflow in parsing the RADIUS authentication packet used in CDMA2000 protocol. The buffer overflow can be exploited to execute arbitrary code with the privileges of the ethereal process (typically "root" when ethereal is being used as a sniffer). To exploit the flaw, an attacker has to either inject the malicious packets into the network traffic being sniffed by ethereal, or entice a client to open a specially crafted packet capture file. A proof-of-concept exploit has been posted. Note that any network applications based on ethereal protocol decoder modules may also be affected.
Status: Vendor confirmed, fix available via CVS. Version 0.10.10 will be released in a day according to the vendor.
Council Site Actions: The affected software is not in production or widespread use, or is not officially supported at any of the council sites. However, two sites said they would patch known installations and a third site notified their affected user base.
Description: Multiple image manipulation utilities and the libXpm library contain vulnerabilities that may be exploited to compromise a UNIX client. (a) X PixMap (XPM) is an ASCII image format popularly used by the X Windows on UNIX systems. The libXpm library provides various functions to store and read XPM image files. The library contains an integer overflow that can be triggered by specifying a negative "bitmap_unit" value in a XPM image, and possibly exploited to execute arbitrary code. In order to exploit the flaw, an attacker has to entice a user (via email or another webpage) to view a malicious XPM file. The technical details can be obtained by examining the Gentoo Linux bug entries and the fixes. (b) The image loading and manipulation utilities - xli, xloadimage and xv contain vulnerabilities that may be exploited to execute arbitrary commands/code on a UNIX client via a specially crafted image. One of the flaws in xli is a well known vulnerability since 2001 for which exploit code is available. Note that these utilities may be linked with browsers such as Mozilla. Hence, a specially crafted webpage or an HTML email may exploit these flaws.
Status: Gentoo has released updates for all the flaws.
Council Site Actions: Most of the council sites are not using the affected software. One site has a very small number of affected systems. However, their UNIX systems are not used for graphics work, thus they have no plans for further action. A second site notified their system support group; they don't plan any further action as well.
Description: Trillian is a widely used instant messenger client that can interoperate with multiple messenger programs such as Yahoo!, MSN, and ICQ etc. The client contains a buffer overflow in handling PNG images. The flaw can be exploited to execute arbitrary code on the system running Trillian. A proof-of-concept PNG image has been posted to the security mailing lists.
Status: Trillian version 3.1 is reportedly not vulnerable.
Council Site Actions: The affected software is not in production or widespread use, or is not officially supported at any of the council sites.
Description: Exploit code has been posted for the overflow in RealPlayer's SMIL processing discussed in the last week's @RISK newsletter. The exploit code can reportedly work on any Windows platform and binds a shell the port 13579/tcp.
Council Site Actions: The affected software is not in production or widespread use, or is not officially supported at any of the council sites. However, one site is in the process of deploying the patches and another site plans to patch computers of users who have a legitimate business need to run the affected software.
This list is compiled by Qualys ( www.qualys.com ) as part of that company's ongoing effort to ensure its vulnerability management web service tests for all known vulnerabilities that can be scanned. As of this week Qualys scans for 4095 unique vulnerabilities. For this special SANS community listing, Qualys also includes vulnerabilities that cannot be scanned remotely.
(c) 2005. All rights reserved. The information contained in this newsletter, including any external links, is provided "AS IS," with no express or implied warranty, for informational purposes only. In some cases, copyright for material in this newsletter may be held by a party other than Qualys (as indicated herein) and permission to use such material must be requested from the copyright owner.
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