A huge week for new vulnerabilities! Windows users face critical new risks to add to last week's DNS cache poisoning problems. Oracle database and application server users also have work to do. CA Brightstor ArcServe users also face more critical vulnerabilities.
Alan
@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).
*************************************************************************
Highlighted Training Program of the Week Rocky Mountain SANS 2005, in Denver in May offers ten immersion tracks plus short courses on Cutting Edge Hacker Techniques, Security Policy Development, Security Awareness Training, and more. Wonderful teachers give you material you can put to work immediately upon returning to the office and present the most current tools and techniques. Details at http://www.sans.org/rockymnt2005 What attendees say: "SANS is the gold standard in network security training, in terms of relevance of material, knowledgeable instructors, and sheer usefulness." (Steve Keifling, SGI)
*************************************************************************
************************* SPONSORED LINKS *******************************
These links may point to sites outside of SANS: 1) Stop worm outbreaks without stopping your business. FREE Worm Suppression white paper. http://www.sans.org/info.php?id=757 2) Find security tools that actually work and listen to interviews with users who have experience with them. Intrusion detection, penetration testing, end point security and more. http://www.sans.org/whatworks
*************************************************************************
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: Microsoft Exchange server supports many SMTP extended verbs that add functionality beyond the SMTP protocol specification. The extended verb used to communicate routing information (X-LINK2STATE) between Exchange servers contains a buffer overflow. The overflow can be exploited to execute arbitrary code with the privileges of the SMTP process, typically Local System. Note that Windows 2000 Exchange servers are critically affected as unauthenticated attackers can leverage this flaw. On Exchange 2003, the overflow can be exploited only by authenticated users, which reduces the impact of the vulnerability.
Status: Apply the patch referenced in the Microsoft Security Bulletin MS05-021.
Council Site Actions: Many of the reporting council sites are responding to this vulnerability. All sites plan to patch during the next regular system update process.
Description: Windows Message Queuing service, an RPC-based service, allows applications running at different times to communicate across networks and systems that may even be temporarily offline. This service contains a buffer overflow that can be triggered by a specially crafted RPC call. An anonymous attacker can exploit this flaw to execute arbitrary code with "Local System" privileges. Note that even though the service is not installed by default on Windows systems, the MSMQ service is used in many e-commerce environments. Exploit code has been included in the Immunitysec CANVAS product.
Status: Apply the patch referenced in the Microsoft Security Bulletin MS05-016. The service binds on multiple high numbered TCP ports. Hence, blocking unsolicited RPC requests above port 1024/tcp, will prevent the attack. E-commerce and other sites using MSMQ should only expose the MSMQ HTTP service to the Internet.
Council Site Actions: One site is remediating its affected systems on a priority basis. Other sites that responded to this item plan to patch during the next regular system update process.
Description: Microsoft has released a cumulative security update for Internet Explorer that patches the following vulnerabilities- (a) A specially crafted webpage using certain Dynamic HTML functions can force Internet Explorer to execute arbitrary code. The problem occurs due to a race condition between IE threads that can be exploited to overwrite a thread's memory with the attacker-supplied data. The technical details and exploit code have been publicly posted. (b) Internet Explorer contains a heap corruption vulnerability that can be triggered by a link of the format '<a href ="hostname over 256 characters">'. A malicious webpage or an HTML email may exploit this flaw to execute arbitrary code on a client system. (c) Internet Explorer Content Advisor (can be reached by clicking Tools->Options->Content on IE menu) can restrict IE users from accessing certain sites. For example, parents can use the Content Advisor to limit access to adult sites for their children. IE contains a buffer overflow that can be triggered by a specially crafted Content Advisor file (PICS format). Note that an attacker would need to convince a user to accept the malicious PICS file in order to exploit the flaw.
Status: Apply the patch referenced in the Microsoft Security Bulletin MS05-020. Note that Internet Explorer exploits are popularly used by malicious sites to install spyware and Trojans on client systems. Hence, this patch should be applied on an expedited basis.
Council Site Actions: All of the reporting council sites are planning to respond to this item. Some plan to patch over the next two weeks and others during their next regularly scheduled system update process.
Description: Oracle has issued a critical patch update (CPU) for various products on April 12, 2005. The patch fixes multiple vulnerabilities including PL/SQL injection flaws and buffer overflows. Also note that this patch addresses many issues with Oracle HTTP server, email server and the calendar software. The technical details and proof-of-concept exploits regarding some of the security issues have been publicly posted. Another security group plans to release the technical details in July 2005.
Council Site Actions: Most of the reporting council sites are responding to this item. Two sites are still investigating what action they will take. The other sites are either in the process of regression testing the patches or have plans to distribute the patches in late April or early May. Several sites commented that the affected Oracle traffic is blocked at their network perimeters; decreasing the level of risk of this vulnerability.
Description: Microsoft has released patches for two buffer overflow vulnerabilities in Microsoft Word. One of the buffer overflows that has been patched was publicly reported in October 2004 along with complete technical details. The technical details about the other overflow have not been publicly disclosed. A webpage or a network share serving a malicious Word document, or an email with a malicious Word attachment, may leverage these flaws to compromise a client. Note that Internet Explorer automatically opens a Word document, which makes it easy to exploit the vulnerabilities via HTTP.
Status: Apply the patch referenced in the Microsoft Security Bulletin MS05-023.
Council Site Actions: Most of the reporting council sites plan to respond to this item and install the patch during their next regularly scheduled system update process. One site commented that they don't distribute patches for applications such as MS Word, but do inform their users about the need to download and install MS Office updates.
Description: Microsoft Office (Word, Excel, PowerPoint) and some WordPerfect and Adobe files are stored in "OLE2" format. This format stores a program name (actually its CLSID) in the OLE2 document that can open the OLE2 file even when the file is re-named with an unknown extension. For instance, if a Word document is renamed with a ".docy" extension, Windows will still open the file with the Word program. A problem arises because Windows does not perform a proper check on the program CLSID stored in an OLE2 document. An attacker can craft a malicious OLE2 document with an unknown extension that contains CLSID of an arbitrary executable. An attacker, for example, can use the CLSID of Microsoft HTML Application Host (MSHTA) in an OLE2 document, to execute arbitrary script code on a user's system. Note that the user would need to double-click the attacker-supplied OLE2 document with an unknown extension. The attacker may be able to fool a user by using visually similar extensions such as ".d0c", ".pppt" etc. Exploit code to craft a malicious OLE2 document has been posted.
Status: Apply the patch referenced in the Microsoft Security Bulletin MS05-016. A workaround to block the email attack vector is to filter file attachments with unknown extensions at the mail gateways. To prevent the attack via HTTP, users should be advised not to open documents with unknown extensions.
Council Site Actions: All of the reporting council sites plan to respond to this item. They will patch during their next regularly scheduled system update process.
Description: MSN messenger contains a buffer overflow that can be triggered by malformed GIF image files. Specifically GIF files with improper height and width cause this overflow that can be exploited to execute arbitrary code with the privileges of the MSN messenger user. A successful attack requires significant user interaction. Prior to sending a specially crafted GIF file, the attacker has to convince an MSN messenger user to add him to the user's contact list.
Status: Apply the patch referenced in the Microsoft Security Bulletin MS05-022.
Council Site Actions: Most of the council sites plan to respond to this item and install the patches during their next regularly scheduled system update process. A few sites commented that they are blocking the affected traffic at their network perimeter points; thus reducing the risk associated with this item. Installation and use of MSN Messenger is not supported by their central IT department, but neither is it blocked.
Description: Windows OS contains the following vulnerabilities in its TCP/IP stack implementation. (a) A specially crafted IP message can lead to a buffer overflow that may be exploited to execute arbitrary code on a Windows system. The technical details regarding this flaw have not been publicly posted yet. (b) An existing TCP connection can be reset by using crafted ICMP or TCP packets. The attacker would need to guess the IP addresses and port numbers used in a TCP connection as well as be able to spoof the source address of ICMP packets to carry these denial-of-service or TCP performance degrading attacks. For more details, please look at item #9 n this newsletter. (c) Land attack, a denial-of service attack known since 1997, can be launched by directing IP packets, with identical source and destination IP addresses, to the target machine. 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); thereby, rendering the system unusable.
Status: Apply the patch referenced in the Microsoft Security Bulletin MS05-019.
Council Site Actions: All of the reporting council sites plan to respond to this item and install the patches during their next regularly scheduled system update process. One site plans to patch all of their systems within one week, as they consider the (a) part of this vulnerability to raise the risk level.
Description: ICMP protocol was designed to communicate information about specific networking failures to hosts or routers on the Internet. The TCP protocol specification defines how a host should respond to the ICMP messages. ICMP error messages may be classified into "hard" and "soft" errors, and contain the source port, destination port and the associated sequence number of the TCP connection. The "hard" errors (e.g. ICMP Destination Unreachable messages with codes 2, 3 and 4) result in an immediate reset of the TCP connection whereas some "soft" errors (e.g. ICMP Source Quench) lead to the performance degradation of the TCP connection. Multiple vendor implementation of the TCP protocol does not sufficiently validate an ICMP error message i.e. the sequence number in the ICMP error message is not checked for correctness . Hence, an ICMP error message containing the correct TCP port numbers, and the same source and destination IP addresses as a TCP connection is processed and acted upon accordingly. An attacker can exploit this to craft ICMP packets that can either reset an existing TCP connection or degrade its performance. Note that for services running on well-known ports, an attacker can reset a TCP connection with 65536 ICMP packets. In addition to the ICMP error messages, an attacker can lower the Maximum Transmission Unit (MTU) size being used in a TCP connection by sending spoofed ICMP Type 3 Code 4 messages. This can lead to degrading the performance of the applications running over TCP. The higher-level protocols that use long-lasting TCP sessions such as the Border Gateway Protocol (BGP) are most affected by this vulnerability. BGP uses persistent TCP connections to exchange routing information with other BGP peers. Repeatedly resetting a BGP connection can lead to denial-of-service to certain portions of the Internet.
Status: Many vendors, including Cisco and Juniper, have confirmed the flaw and have made updates available. For a detailed status on other vendors, please refer to the UK NISCC advisory below. A possible workaround is to filter ICMP messages at the network perimeter and allow only certain types of ICMP messages into the network.
Council Site Actions: One site considers a this low risk vulnerability due to the difficulty of exploitation vs. other DoS mechanisms. Thus they don't plan any action. Most of the other reporting council sites plan to patch their systems during their next regularly scheduled system update process.
Description: Computer Associates BrightStor ARCserve Backup products provide backup services for Windows, NetWare, Linux and UNIX. The backup agent, that listens on port 6050/tcp by default, contains a buffer overflow. The flaw can be triggered by sending a large string followed by the "option" field set to 0, 3 or 1000, and exploited to execute arbitrary code with "SYSTEM" privileges. Exploit code has been included in the Metasploit project.
Status: CA confirmed, updates available. A workaround is to block traffic to port 6050/tcp at the network perimeter.
Council Site Actions: Three sites responded to this item. One site plans to patch during its next regular patching cycle. The second site plans to scan its network on TCP port 6050 to obtain a preliminary list of systems that may be affected and then determine action. They may have some systems directly exposed to the Internet. The final site is in the process of migrating away from CA backup products and will proceed with patching its systems to limit exposure.
Description: OpenOffice software is a multi-platform open-source office productivity software that emulates other commercial products like Microsoft Office. This software contains a heap-based overflow that can be triggered by a malformed ".doc" (Word) file. The flaw can be exploited to execute arbitrary code on the client system with the privileges of the logged-on user. If OpenOffice is set as the default application to handle .doc documents, browsing a malicious page or clicking a Word attachment in an email, is sufficient to trigger the flaw. The technical details that can be used to craft a malicious .doc document have been posted.
Status: OpenOffice confirmed, patches available. Users of 2.0 Beta should download version 1.9.95.
Council Site Actions: Only one site responded to this item. They have around 400 systems where the system configuration and/or user practices would lead to some risk of opening a malicious document. They plan to update their systems this month.
Description: IBM Lotus Domino multi-platform server software is designed to handle email and scheduling for large enterprises. The HTTP service in the Lotus Domino server contains a buffer overflow that can be triggered by an HTTP POST request containing a large amount of data for certain time/date fields. The researchers claim to have discovered six attack vectors to exploit this flaw that, they say, will be disclosed in July 2005. Lotus Domino administrators should upgrade their servers before July. Note that the flaw is marked as "MODERATE" due to unavailability of complete technical details and the lack of information regarding the credentials required to exploit this flaw. According to the @RISK recommendations, "MODERATE" rated flaws should be attended to within 15 business days.
Status: IBM has acknowledged the flaw and has released an update.
Council Site Actions: Two of the reporting council sites are running the affected software. Both plan to patch during their next regularly scheduled system update process.
Description: FocalPoint server is the central server of the Veritas i3 Application Performance Management suite. NGSSoftware has reported a critical flaw in this server. Note that the @RISK rating for this flaw is "MODERATE" due to lack of any further information but "critical" ratings from the NGSSoftware typically implies that a remote compromise of the FocalPoint server may be possible by unauthenticated attackers. This server is bundled with other servers such as Oracle. Hence, FocalPoint users should upgrade their servers prior to the release of technical details of the flaw (currently schedules for July 2005).
Council Site Actions: The affected software or vulnerable configuration 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: Exploit code has been posted for the Microsoft Jet Database Engine flaw discussed in the last @RISK newsletter. Note that there is no patch available from Microsoft yet.
Council Site Actions: The affected council sites are still waiting for additional information and a patch from the vendor.
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 4224 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.
==end== Subscriptions: @RISK is distributed free of charge to people responsible for managing and securing information systems and networks. You may forward this newsletter to others with such responsibility inside or outside your organization.
To subscribe, at no cost, go to https://portal.sans.org where you may also request subscriptions to any of SANS other free newsletters.
To change your subscription, address, or other information, visit http://portal.sans.org
Copyright 2005. All rights reserved. No posting or reuse allowed, other that listed above, without prior written permission.