CVE-2010-0162 in SeaMonkey
Summary
by MITRE
Mozilla Firefox 3.0.x before 3.0.18 and 3.5.x before 3.5.8, and SeaMonkey before 2.0.3, does not properly support the application/octet-stream content type as a protection mechanism against execution of web script in certain circumstances involving SVG and the EMBED element, which allows remote attackers to bypass the Same Origin Policy and conduct cross-site scripting (XSS) attacks via an embedded SVG document.
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Analysis
by VulDB Data Team • 05/01/2026
This vulnerability resides in the web browser security model of mozilla firefox and seamonkey applications where improper handling of content type headers creates a significant bypass opportunity for malicious actors. The flaw specifically affects versions of firefox 3.0.x before 3.0.18 and 3.5.x before 3.5.8 along with seamonkey versions before 2.0.3. The vulnerability stems from the browser's inadequate enforcement of the application/octet-stream content type which should normally act as a protective mechanism preventing automatic execution of web scripts. When combined with svg documents and the embed element, this weakness allows attackers to circumvent the same origin policy that normally protects users from cross site scripting attacks.
The technical implementation of this vulnerability involves the browser's content disposition handling mechanism where the application/octet-stream content type is not being properly respected. This content type should trigger a download behavior rather than inline execution, but in affected versions the browser fails to enforce this distinction properly. When an attacker crafts a malicious svg document that gets embedded within another page, the browser's failure to properly handle the content type allows the embedded content to execute with the privileges of the parent document. This creates a scenario where javascript code within the embedded svg can access the parent page's resources and execute arbitrary code against the user's browsing session.
The operational impact of this vulnerability is severe as it enables attackers to conduct sophisticated cross site scripting attacks that can bypass fundamental browser security restrictions. The same origin policy is a core security mechanism that prevents scripts from one domain from accessing resources of another domain without explicit permission, but this vulnerability allows attackers to circumvent that protection entirely. An attacker could potentially steal session cookies, perform actions on behalf of the user, or redirect users to malicious sites without their knowledge. The attack vector is particularly dangerous because it can be executed through standard web browsing activities involving embedded svg content, making it difficult for users to identify when they are being targeted.
This vulnerability maps to CWE-1021 which specifically addresses improper restriction of operations within a limited context and aligns with ATT&CK technique T1059.007 for command and scripting interpreter. The attack scenario represents a classic privilege escalation through content type manipulation where the attacker leverages browser implementation gaps to gain unauthorized access to user resources. Organizations should immediately update to patched versions of firefox and seamonkey, as the fix involves proper enforcement of content type handling. Additionally, administrators should implement web application firewalls that can detect and block suspicious content type headers, and users should be educated about the dangers of visiting untrusted websites that may contain malicious embedded svg content.
The broader implications of this vulnerability highlight the complexity of modern web browser security models and the challenges of implementing comprehensive protection mechanisms. Content type handling represents just one layer in a multi-layered security approach, yet its failure can compromise entire browsing sessions. This particular flaw demonstrates how seemingly minor implementation details in browser security can create significant attack surfaces that adversaries can exploit to bypass fundamental protections. The vulnerability also underscores the importance of proper input validation and content disposition handling in web applications, as similar issues could potentially exist in other components of the browser ecosystem that rely on similar content type interpretation mechanisms.