+---------------------------------------------------------------------+ | LinuxSecurity.com Weekly Newsletter | | December 30th, 2005 Volume 6, Number 52a | +---------------------------------------------------------------------+ Editors: Dave Wreski Benjamin D. Thomas dave@xxxxxxxxxxxxxxxxx ben@xxxxxxxxxxxxxxxxx Linux Advisory Watch is a comprehensive newsletter that outlines the security vulnerabilities that have been announced throughout the week. It includes pointers to updated packages and descriptions of each vulnerability. This week, advisories were released for phpbb2, ketm, tkdiff, dhis-tools-dns, Mantis, NDB, rssh, OpenMotif, scponly, msec, fetchmail, cpio, php-mbstring, and libgphoto. The distributors include Debian, Gentoo, and Mandriva. ---- Earn an NSA recognized IA Masters Online The NSA has designated Norwich University a center of Academic Excellence in Information Security. Our program offers unparalleled Infosec management education and the case study affords you unmatched consulting experience. Using interactive e-Learning technology, you can earn this esteemed degree, without disrupting your career or home life. http://www.msia.norwich.edu/linsec ---- IPv6 approach for TCP SYN Flood attack over VoIP, Part II By: Suhas Desai 3. Classification of DoS Attacks There are several general categories of DoS attacks. Some groups divide attacks into three classes: bandwidth attacks, protocol attacks, and logic attacks. Following are brief descriptions of some common types of DoS attacks. 3.1 Bandwidth attacks Bandwidth attacks are relatively straightforward attempts to consume resources, such as network bandwidth or equipment throughput. High-data- volume attacks can consume all available bandwidth between an ISP and your site. The link fills up, and legitimate traffic slows down. Timeouts may occur, causing retransmission, generating even more traffic. An attacker can consume bandwidth by transmitting any traffic at all on your network connection. A basic flood attack might use UDP or ICMP packets to simply consume all available bandwidth. For that matter, an attack could consist of TCP or raw IP packets, as long as the traffic is routed to your network. A simple bandwidth-consumption attack can exploit the throughput limits of servers or network equipment by focusing on high packet rates.sending large numbers of small packets. High-packet-rate attacks typically overwhelm network equipment before the traffic reaches the limit of available bandwidth. Routers, servers, and firewalls all have constraints on input-output processing, interrupt processing, CPU, and memory resources. Network equipment that reads packet headers to properly route traffic becomes stressed handling the high packet rate (pps), not the volume of the data (Mbps). In practice, denial of service is often accomplished by high packet rates, not by sheer traffic volume. 3.2 Protocol Attacks The basic flood attack can be further refined to take advantage of the inherent design of common network protocols. These attacks do not directly exploit weaknesses in TCP/IP stacks or network applications but, instead, use the expected behavior of protocols such as TCP, UDP, and ICMP to the attacker's advantage. Examples of protocol attacks include the following: 3.2.1 SYN flood is an asymmetric resource starvation attack in which the attacker floods the victim with TCP SYN packets and the victim allocates resources to accept perceived incoming connections. As mentioned above, the proposed Host Identity Payload and Protocol (HIP) are designed to mitigate the effects of a SYN flood attack. Another technique, SYN Cookies is implemented in some TCP/IP stacks. 3.2.2 Smurf is an asymmetric reflector attack that targets a vulnerable networkm broadcast address with ICMP ECHO REQUEST packets and spoofs the source of the victim. 3.2.3 Fraggle is a variant of smurf that sends UDP packets to echo or chargen ports on broadcast addresses and spoofs the source of the victim. Read Entire Article: http://www.linuxsecurity.com/content/view/121124/49/ ---------------------- Linux File & Directory Permissions Mistakes One common mistake Linux administrators make is having file and directory permissions that are far too liberal and allow access beyond that which is needed for proper system operations. A full explanation of unix file permissions is beyond the scope of this article, so I'll assume you are familiar with the usage of such tools as chmod, chown, and chgrp. If you'd like a refresher, one is available right here on linuxsecurity.com. http://www.linuxsecurity.com/content/view/119415/49/ --- Buffer Overflow Basics A buffer overflow occurs when a program or process tries to store more data in a temporary data storage area than it was intended to hold. Since buffers are created to contain a finite amount of data, the extra information can overflow into adjacent buffers, corrupting or overwriting the valid data held in them. http://www.linuxsecurity.com/content/view/119087/49/ --- Review: The Book of Postfix: State-of-the-Art Message Transport I was very impressed with "The Book of Postfix" by authors Ralf Hildebrandt and Pattrick Koetter and feel that it is an incredible Postfix reference. It gives a great overall view of the operation and management of Postfix in an extremely systematic and practical format. It flows in a logical manner, is easy to follow and the authors did a great job of explaining topics with attention paid to real world applications and how to avoid many of the associated pitfalls. I am happy to have this reference in my collection. http://www.linuxsecurity.com/content/view/119027/49/ -------- --> Take advantage of the LinuxSecurity.com Quick Reference Card! --> http://www.linuxsecurity.com/docs/QuickRefCard.pdf +---------------------------------+ | Distribution: Debian | ----------------------------// +---------------------------------+ * Debian: New phpbb2 packages fix several vulnerabilities 22nd, December, 2005 Updated package. http://www.linuxsecurity.com/content/view/121073 * Debian: New ketm packages fix privilege escalation 23rd, December, 2005 Updated package. http://www.linuxsecurity.com/content/view/121092 * Debian: New ketm packages fix privilege escalation 23rd, December, 2005 Updated package. http://www.linuxsecurity.com/content/view/121094 * Debian: New tkdiff packages fix insecure temporary file creation 27th, December, 2005 Updated package. http://www.linuxsecurity.com/content/view/121103 * Debian: New dhis-tools-dns packages fix insecure temporary file creation 27th, December, 2005 Updated package. http://www.linuxsecurity.com/content/view/121107 * Debian: New tkdiff packages fix insecure temporary file creation 29th, December, 2005 Updated package. http://www.linuxsecurity.com/content/view/121115 +---------------------------------+ | Distribution: Gentoo | ----------------------------// +---------------------------------+ * Gentoo: Mantis Multiple vulnerabilities 22nd, December, 2005 Mantis is affected by multiple vulnerabilities ranging from file upload and SQL injection to cross-site scripting and HTTP response splitting. http://www.linuxsecurity.com/content/view/121082 * Gentoo: Dropbear Privilege escalation 23rd, December, 2005 A buffer overflow in Dropbear could allow authenticated users to execute arbitrary code as the root user. http://www.linuxsecurity.com/content/view/121086 * Gentoo: NBD Tools Buffer overflow in NBD server 23rd, December, 2005 The NBD server is vulnerable to a buffer overflow that may result in the execution of arbitrary code. http://www.linuxsecurity.com/content/view/121093 * Gentoo: rssh Privilege escalation 27th, December, 2005 Local users could gain root privileges by chrooting into arbitrary directories. http://www.linuxsecurity.com/content/view/121109 * Gentoo: OpenMotif, AMD64 x86 emulation X libraries Buffer 28th, December, 2005 Two buffer overflows have been discovered in libUil, part of the OpenMotif toolkit, that can potentially lead to the execution of arbitrary code. http://www.linuxsecurity.com/content/view/121114 * Gentoo: scponly Multiple privilege escalation issues 29th, December, 2005 Local users can exploit an scponly flaw to gain root privileges, and scponly restricted users can use another vulnerability to evade shell restrictions. http://www.linuxsecurity.com/content/view/121116 +---------------------------------+ | Distribution: Mandriva | ----------------------------// +---------------------------------+ * Mandriva: Updated msec packages fixes various bugs 22nd, December, 2005 Bugs in the msec package have been corrected: msec wasn't properly parsing the output on security checks to check ownership of files, reporting files as unowned when they were in fact properly owned by a valid user. http://www.linuxsecurity.com/content/view/121085 * Mandriva: Updated fetchmail packages fix vulnerability 23rd, December, 2005 Fetchmail before 6.3.1 and before 6.2.5.5, when configured for multidrop mode, allows remote attackers to cause a DoS (application crash) by sending messages without headers from upstream mail servers. http://www.linuxsecurity.com/content/view/121095 * Mandriva: Updated cpio packages fix buffer overflow on x86_64 23rd, December, 2005 A buffer overflow in cpio 2.6 on 64-bit platforms could allow a local user to create a DoS (crash) and possibly execute arbitrary code when creating a cpio archive with a file whose size is represented by more than 8 digits. http://www.linuxsecurity.com/content/view/121096 * Mandriva: Updated digikamimageplugins packages fix showfoto crash issue. 26th, December, 2005 A previous update of DigiKam (MDKA-2005:059) bumped the version to 0.8.0. After this update, Narfi Stefansson reported that showfoto, from digikamimageplugins was crashing when trying to use "Free Rotation". This update bumps digikamimageplugins to version 0.8.0 also. http://www.linuxsecurity.com/content/view/121101 * Mandriva: Updated php/php-mbstring packages fix mail injection vulnerability 27th, December, 2005 A CRLF injection vulnerability in the mb_send_mail function in PHP before 5.1.0 might allow remote attackers to inject arbitrary e-mail headers via line feeds (LF) in the "To" address argument, when using sendmail as the MTA (mail transfer agent). http://www.linuxsecurity.com/content/view/121110 * Mandriva: Updated libgphoto packages fixes issue with some cameras 29th, December, 2005 The hotplug usermap has been restored for this package because it is used by HAL to correctly detect digital cameras which are not using USB Mass storage (for instance, all Canon digital cameras, as well as some Nikon ones and all PTP cameras). This should allow gnome-volume-manager to automatically popup a "Do you want to import photos?" dialog when the camera is plugged in. http://www.linuxsecurity.com/content/view/121117 ------------------------------------------------------------------------ Distributed by: Guardian Digital, Inc. LinuxSecurity.com To unsubscribe email vuln-newsletter-request@xxxxxxxxxxxxxxxxx with "unsubscribe" in the subject of the message. ------------------------------------------------------------------------