CVE-2010-2648 in Chrome
Summary
by MITRE
The implementation of the Unicode Bidirectional Algorithm (aka Bidi algorithm or UBA) in Google Chrome before 5.0.375.99 allows remote attackers to cause a denial of service (memory corruption) or possibly have unspecified other impact via unknown vectors.
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Analysis
by VulDB Data Team • 09/20/2021
The vulnerability identified as CVE-2010-2648 represents a critical flaw in Google Chrome's handling of the Unicode Bidirectional Algorithm, a fundamental component for proper text rendering in internationalized web environments. This algorithm, also known as UBA, is essential for correctly displaying text that contains both left-to-right and right-to-left character sequences, such as Arabic and Hebrew text mixed with English. The flaw exists in Chrome versions prior to 5.0.375.99, where the implementation of this complex text processing mechanism contains memory corruption vulnerabilities that can be exploited by remote attackers.
The technical nature of this vulnerability stems from improper memory management within the Unicode Bidirectional Algorithm implementation, which processes text directionality for display purposes. When Chrome encounters specially crafted web content that triggers specific Unicode character sequences, the flawed implementation can lead to memory corruption conditions that may result in application crashes or potentially more severe consequences. This type of vulnerability falls under the CWE-121 category of stack-based buffer overflow, though the specific manifestation involves heap corruption during Unicode text processing operations. The vulnerability's impact extends beyond simple denial of service, as the memory corruption could potentially enable arbitrary code execution depending on the attack vector and system configuration.
The operational impact of this vulnerability is significant for users of affected Chrome versions, as it creates a remote attack surface that requires no user interaction beyond visiting a malicious website. Attackers can exploit this weakness through various vectors including malicious web pages, compromised advertising networks, or phishing sites that contain crafted Unicode text sequences designed to trigger the memory corruption. The vulnerability's potential for unspecified other impacts suggests that beyond the immediate denial of service, there may be opportunities for privilege escalation or information disclosure depending on the execution environment and the specific nature of the memory corruption. This aligns with ATT&CK technique T1203 which covers legitimate programs with persistence mechanisms that can be abused for malicious purposes.
Mitigation strategies for this vulnerability primarily involve immediate patching of Chrome installations to version 5.0.375.99 or later, where Google has implemented fixes for the Unicode Bidirectional Algorithm implementation. Organizations should also consider implementing web content filtering solutions that can detect and block suspicious Unicode sequences, though such measures may impact legitimate internationalized web content. Browser security updates should be prioritized as part of regular maintenance procedures, and users should be educated about the risks of visiting untrusted websites. Additionally, system administrators should monitor for exploitation attempts through network intrusion detection systems that can identify patterns associated with Unicode-based attack vectors. The vulnerability highlights the importance of proper memory management in complex text processing algorithms and serves as a reminder that seemingly benign internationalization features can become attack vectors when not properly implemented and tested.