CVE-2011-1798 in Chrome
Summary
by MITRE
rendering/svg/RenderSVGText.cpp in WebCore in WebKit in Google Chrome before 11.0.696.65 does not properly perform a cast of an unspecified variable during an attempt to handle a block child, which allows remote attackers to cause a denial of service (application crash) or possibly have unknown other impact via a crafted text element in an SVG document.
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Analysis
by VulDB Data Team • 04/10/2022
The vulnerability described in CVE-2011-1798 resides within the WebCore component of WebKit, specifically in the rendering module responsible for handling Scalable Vector Graphics documents. This flaw manifests in the RenderSVGText.cpp file where an improper type casting operation occurs during the processing of block child elements within SVG text rendering. The vulnerability affects Google Chrome versions prior to 11.0.696.65, representing a critical security gap that could be exploited by malicious actors to disrupt normal browser operations. The issue stems from inadequate input validation and type safety mechanisms when processing specially crafted SVG text elements that contain block child structures.
The technical implementation of this vulnerability involves a type casting error that occurs when the WebKit rendering engine attempts to process SVG text elements containing block child nodes. During this process, an unspecified variable undergoes an improper cast operation that leads to memory corruption or invalid memory access patterns. This casting failure results in the browser application crashing when it encounters malformed SVG content that triggers the specific code path. The vulnerability demonstrates characteristics of a buffer overflow or type confusion issue, where the improper casting leads to unpredictable behavior in the rendering engine's memory management. The flaw is particularly concerning because SVG processing occurs in the browser's rendering layer, making it accessible through standard web content delivery mechanisms.
From an operational perspective, this vulnerability enables remote attackers to execute denial of service attacks against targeted systems by simply delivering a maliciously crafted SVG document through web pages or embedded content. The impact extends beyond simple application crashes, as the improper casting could potentially lead to more severe consequences including arbitrary code execution or information disclosure depending on the exploitation context. The vulnerability's exploitability is high since it only requires the victim to view a web page containing the malicious SVG content, making it particularly dangerous in phishing campaigns or compromised websites. Attackers can leverage this weakness to disrupt user browsing sessions, potentially causing persistent service interruption or creating opportunities for more sophisticated attacks.
The vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and CWE-122, which covers buffer overflow vulnerabilities. It also maps to ATT&CK technique T1203, which involves exploitation of web applications through browser-based attacks. The issue represents a classic software quality flaw that demonstrates inadequate bounds checking and type validation in the rendering pipeline. Mitigation strategies should include immediate patching of affected Chrome versions to 11.0.696.65 or later, implementation of content security policies that restrict SVG content processing, and deployment of web application firewalls that can detect and block malicious SVG patterns. Organizations should also consider implementing browser hardening measures and monitoring for unusual browser crash patterns that might indicate exploitation attempts. The vulnerability underscores the importance of robust input validation and type safety in browser rendering engines, particularly when processing complex multimedia content types like SVG graphics.