USN-296-1: firefox vulnerabilities

9 June 2006

firefox vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 6.06 LTS

Software Description


Jonas Sicking discovered that under some circumstances persisted XUL attributes are associated with the wrong URL. A malicious web site could exploit this to execute arbitrary code with the privileges of the user. (MFSA 2006-35, CVE-2006-2775)

Paul Nickerson discovered that content-defined setters on an object prototype were getting called by privileged UI code. It was demonstrated that this could be exploited to run arbitrary web script with full user privileges (MFSA 2006-37, CVE-2006-2776). A similar attack was discovered by moz_bug_r_a4 that leveraged SelectionObject notifications that were called in privileged context. (MFSA 2006-43, CVE-2006-2777)

Mikolaj Habryn discovered a buffer overflow in the crypto.signText() function. By tricking a user to visit a site with an SSL certificate with specially crafted optional Certificate Authority name arguments, this could potentially be exploited to execute arbitrary code with the user’s privileges. (MFSA 2006-38, CVE-2006-2778)

The Mozilla developer team discovered several bugs that lead to crashes with memory corruption. These might be exploitable by malicious web sites to execute arbitrary code with the privileges of the user. (MFSA 2006-32, CVE-2006-2779, CVE-2006-2780, CVE-2006-2788)

Chuck McAuley reported that the fix for CVE-2006-1729 (file stealing by changing input type) was not sufficient to prevent all variants of exploitation. (MFSA 2006-41, CVE-2006-2782)

Masatoshi Kimura found a way to bypass web input sanitizers which filter out JavaScript. By inserting ‘Unicode Byte-order-Mark (BOM)’ characters into the HTML code (e. g. ‘<scr[BOM]ipt>’), these filters might not recognize the tags anymore; however, Firefox would still execute them since BOM markers are filtered out before processing the page. (MFSA 2006-42, CVE-2006-2783)

Paul Nickerson noticed that the fix for CVE-2005-0752 (JavaScript privilege escalation on the plugins page) was not sufficient to prevent all variants of exploitation. (MFSA 2006-36, CVE-2006-2784)

Paul Nickerson demonstrated that if an attacker could convince a user to right-click on a broken image and choose “View Image” from the context menu then he could get JavaScript to run on a site of the attacker’s choosing. This could be used to steal login cookies or other confidential information from the target site. (MFSA 2006-34, CVE-2006-2785)

Kazuho Oku discovered various ways to perform HTTP response smuggling when used with certain proxy servers. Due to different interpretation of nonstandard HTTP headers in Firefox and the proxy server, a malicious web site can exploit this to send back two responses to one request. The second response could be used to steal login cookies or other sensitive data from another opened web site. (MFSA 2006-33, CVE-2006-2786)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 6.06 LTS
firefox - 1.5.dfsg+

To update your system, please follow these instructions:

After a standard system upgrade you need to restart Firefox to effect the necessary changes.

Please note that Firefox 1.0.8 in Ubuntu 5.10 and Ubuntu 5.04 are also affected by these problems. Updates for these Ubuntu releases will be delayed due to upstream dropping support for this Firefox version. We strongly advise that you disable JavaScript to disable the attack vectors for most vulnerabilities if you use one of these Ubuntu versions.