CVE-2008-0016 in Firefox
Summary
by MITRE
Stack-based buffer overflow in the URL parsing implementation in Mozilla Firefox before 2.0.0.17 and SeaMonkey before 1.1.12 allows remote attackers to execute arbitrary code via a crafted UTF-8 URL in a link.
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Analysis
by VulDB Data Team • 08/17/2019
The vulnerability identified as CVE-2008-0016 represents a critical stack-based buffer overflow within the URL parsing functionality of Mozilla Firefox and SeaMonkey web browsers. This flaw exists in versions prior to Firefox 2.0.0.17 and SeaMonkey 1.1.12, where the implementation fails to properly validate input lengths when processing UTF-8 encoded URLs contained within hyperlinks. The vulnerability stems from insufficient bounds checking during the parsing of Unicode character sequences, creating a condition where maliciously crafted URLs can exceed the allocated buffer space on the stack. This particular implementation flaw aligns with CWE-121, which specifically addresses stack-based buffer overflow conditions where insufficient space is allocated for data that may exceed expected boundaries.
The technical exploitation of this vulnerability occurs when a victim visits a web page containing a specially crafted URL that utilizes UTF-8 encoding to trigger the buffer overflow condition. The malicious URL contains character sequences that, when processed by the vulnerable parsing routine, cause data to overwrite adjacent memory locations on the stack. This overwrite can potentially corrupt the return address of the calling function, allowing an attacker to redirect program execution to malicious code injected into the buffer space. The attack vector is particularly insidious because it leverages the standard hyperlink mechanism, making it difficult for users to distinguish between legitimate and malicious content. This vulnerability directly maps to ATT&CK technique T1203, which involves the exploitation of software vulnerabilities to gain code execution capabilities through crafted input.
The operational impact of CVE-2008-0016 extends beyond simple code execution, as successful exploitation can lead to complete system compromise and unauthorized access to sensitive user data. Attackers can leverage this vulnerability to install malware, steal cookies and session information, or perform man-in-the-middle attacks against the victim's browsing session. The widespread adoption of Firefox and SeaMonkey at the time of this vulnerability meant that a significant number of users were potentially exposed to this risk. The attack requires no special privileges from the victim beyond normal web browsing activities, making it particularly dangerous in enterprise environments where users may not be security-aware. The vulnerability also demonstrates the importance of proper input validation in web browser implementations, as the flaw existed in the fundamental parsing mechanism that handles all user-provided URLs.
Mitigation strategies for this vulnerability primarily focus on immediate software updates and patches provided by Mozilla. Organizations should prioritize deployment of Firefox 2.0.0.17 and SeaMonkey 1.1.12 releases, which contain the necessary fixes to address the buffer overflow condition. Additionally, network administrators can implement URL filtering solutions that block access to known malicious domains, though this approach provides only partial protection since the vulnerability can be exploited through any crafted UTF-8 URL. Browser security enhancements such as address space layout randomization and stack canaries can provide additional defense-in-depth measures, though these protections are secondary to the core patching solution. The vulnerability also highlights the necessity of regular security assessments and the importance of maintaining current browser versions to protect against known exploits. This case study exemplifies the critical nature of input validation in web applications and the severe consequences that can result from inadequate bounds checking in parsing routines, reinforcing the principles outlined in security standards such as the OWASP Top Ten and NIST guidelines for secure coding practices.