CVE-2011-1117 in Chrome
Summary
by MITRE
Google Chrome before 9.0.597.107 does not properly handle XHTML documents, which allows remote attackers to cause a denial of service or possibly have unspecified other impact via unknown vectors that lead to "stale nodes."
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Analysis
by VulDB Data Team • 10/18/2021
The vulnerability identified as CVE-2011-1117 affects Google Chrome versions prior to 9.0.597.107 and stems from improper handling of XHTML documents within the browser's rendering engine. This flaw manifests when Chrome processes XHTML content that contains certain malformed or improperly structured elements, leading to instability in the browser's document object model. The issue specifically involves the browser's treatment of "stale nodes" which occur when the DOM tree becomes inconsistent due to improper node management during document parsing. These stale nodes represent memory references to elements that have been removed or modified but not properly cleaned up, creating a condition where subsequent operations on the document tree can trigger unexpected behavior.
The technical implementation of this vulnerability lies in Chrome's HTML and XHTML parsing logic within its WebKit-based rendering engine. When processing XHTML documents, the browser fails to properly validate the structural integrity of the document during parsing operations, particularly when encountering elements that may have been modified or removed from the original document structure. This improper handling creates opportunities for attackers to craft malicious XHTML content that, when rendered by the vulnerable browser, causes the browser to maintain references to deleted or modified DOM nodes. The stale node condition can lead to memory corruption or browser instability, as the rendering engine attempts to access invalid memory locations or perform operations on nodes that no longer exist in the document tree.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable more sophisticated attacks. While the primary effect is a denial of service that can cause the browser to crash or become unresponsive, the underlying stale node condition could theoretically be exploited to execute arbitrary code or escalate privileges. Attackers can craft specially formatted XHTML documents that trigger the stale node condition when loaded in the vulnerable browser, potentially leading to complete browser compromise. The vulnerability affects users who encounter malicious XHTML content through various attack vectors including phishing emails, compromised websites, or malicious advertisements that deliver the crafted content directly to the browser.
Security researchers have classified this vulnerability under CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer, as the stale node condition represents a classic buffer overflow scenario where memory references become invalid. The issue also aligns with ATT&CK technique T1211 Exploitation for Defense Evasion, as attackers can leverage this vulnerability to maintain persistent access by causing browser instability that may be exploited further. Organizations should prioritize immediate patching of affected Chrome installations to mitigate the risk of exploitation, as the vulnerability represents a significant threat to browser security and user safety. The remediation process requires updating Chrome to version 9.0.597.107 or later, which includes proper handling of XHTML document structures and implementation of robust node management procedures to prevent stale node conditions from occurring during document parsing operations.