Security bug researchers (and others with more malicious purpose) have been focusing on Apple OS X, and they have been very successful. Quoting from the first item in this week's issue: "...several [OS X] vulnerabilities are exploitable by remote users. Several file format vulnerabilities are also present. Several implementation errors also exist in the Mac OS X application firewall."
If you are ever asked which operating system is safer, the following 'non-aligned' rule may be of some help. Given a fixed level of programming skill, the number of vulnerabilities in software is directly proportional to the number of lines of code and inversely proportional to the length of time the software has been in wide use. Large numbers of critical vulnerabilities are being, and were bound to be, discovered in Apple's operating system because Steve Jobs may design better hardware, but his programmers are no better at writing secure code than programmers in other software organizations. 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).
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Part I for this issue has been compiled by Rob King 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: Apple Mac OS X contains multiple vulnerabilities. Vulnerabilities range in severity from remote code execution to information disclosure and denials-of-service. A large number of the vulnerabilities are exploitable only by local users or users on the local network, but several vulnerabilities are exploitable by remote users. Several file format vulnerabilities are also present. Several implementation errors also exist in the Mac OS X application firewall. The firewall flaws affect only Mac OS X 10.5. The other vulnerabilities affect only Mac OS X 10.4.10 and prior. Some of these vulnerabilities have been discussed in previous issues of @RISK. Technical details are available for some of these vulnerabilities.
Status: Apple confirmed, updates available.
Description: Samba is an open source suite of applications designed to provide interoperability between clients using Microsoft Windows and servers running Unix or Unix-like operating systems. Several flaws in the handling of various requests could lead to a buffer overflow. Successfully exploiting this buffer overflow would allow an attacker to execute arbitrary code with the privileges of the vulnerable process, often root. Full technical details for these vulnerabilities is available via source code analysis.
Status: Samba confirmed, updates available.
Description: The Microsoft Windows Shell, the portion of the operating system responsible for managing the user interface, contains a flaw in its handling of URIs passed to it by applications. A malicious URI passed to an application that is then passed to the shell could exploit this vulnerability to execute arbitrary commands with the privileges of the current user. Numerous applications are known to pass URIs to the Windows Shell in an insecure manner. Technical details and several proofs-of-concept are available for this vulnerability. This vulnerability has been discussed in a previous issue of @RISK.
Status: Microsoft confirmed, updates available.
Description: Microsoft's DNS server, shipped as part of Microsoft's server offerings, contain a flaw in its algorithm used to generate random transaction ID numbers. These numbers are used by the DNS protocol to identify and pair requests and responses. If the transaction ID is guessed, an attacker could provide a false reply to a DNS server or otherwise impersonate actors in other requests, and potentially cause the vulnerable DNS server to return false responses to its clients. This would allow an attacker to divert traffic to attacker-controlled or otherwise malicious locations. The random number generation flaw would allow an attacker who could observe several transaction IDs to predict future transaction IDs. This flaw may be related to a flaw in ISC BIND, the de facto DNS server software for Unix and other systems. The flaw in ISC BIND was discussed in an earlier edition of @RISK. Multiple proofs-of-concept are publicly available for this vulnerability.
Status: Microsoft confirmed, updates available.
Description: The Linux kernel, the core of operating systems generally described as Linux, contains a flaw in its handling of the Common Internet Filesystem (CIFS) protocol. The CIFS protocol is based on the older Server Message Block (SMB) protocol, used primarily by Microsoft Windows systems to share filesystems and other resources. A malicious CIFS server could trigger a buffer overflow in the SendReceive()kernel function in any Linux clients connected to the server. This would allow an attacker to execute arbitrary code with kernel level privileges. Full technical details for this vulnerability are publicly available.
Status: Linux kernel developers have confirmed the flaw. A preliminary patch is available.
Description: FLAC is the Free Lossless Audio Codec, used to compress audio data. It is supported by many popular software and hardware media players. Several flaws have been found in multiple FLAC parsers. A specially crafted FLAC file could trigger one of these vulnerabilities. Several of these vulnerabilities would allow an attacker to execute arbitrary code with the privileges of the current user. Note that, depending on the application used and system configuration, FLAC files may be opened automatically. Some of these vulnerabilities have been discussed in earlier issues of @RISK. Technical details for these vulnerabilities is available via source code analysis.
Status: LibFLAC confirmed, updates available.
Description: Apple Safari is Apple's web browser product for Apple Mac OS X and Microsoft Windows. The Microsoft Windows version contains a buffer overflow vulnerability in its handling of certain JavaScript constructs. A malicious web page containing a specially crafted JavaScript script could trigger this vulnerability and execute arbitrary code with the privileges of the current user. A proof-of-concept for this vulnerability is publicly available. Note that the version of Safari for Mac OS X does not appear to be affected. Several other vulnerabilities, including information disclosure and denial-of-service vulnerabilities are addressed by this update.
Status: Apple confirmed, updates available.
Description: The Linux kernel, the core of operating systems generally described as Linux, contains a flaw in its handling of Transmission Control Protocol (TCP) packets. A specially crafted sequence of TCP packets could trigger a denial-of-service condition, leading to a system crash. Practically all systems exposed to the internet expose themselves to TCP packets, making this vulnerability potentially widely exploitable. It is not believed to be possible to leverage this vulnerability to lead to remote code execution. Full technical details are publicly available for this vulnerability.
Status: Linux kernel developers confirmed, updates available.
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 5549 unique vulnerabilities. For this special SANS community listing, Qualys also includes vulnerabilities that cannot be scanned remotely.
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