CVE-2017-5066 in Chrome
Summary
by MITRE
Insufficient consistency checks in signature handling in the networking stack in Google Chrome prior to 58.0.3029.81 for Mac, Windows, and Linux, and 58.0.3029.83 for Android, allowed a remote attacker to incorrectly accept a badly formed X.509 certificate via a crafted HTML page.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 12/20/2020
The vulnerability identified as CVE-2017-5066 represents a critical flaw in Google Chrome's certificate validation mechanism within its networking stack. This issue affects multiple platform versions including Mac, Windows, Linux, and Android operating systems, with specific patched versions being 58.0.3029.81 for mobile platforms and 58.0.3029.83 for desktop environments. The vulnerability stems from insufficient consistency checks during signature handling processes, which creates a pathway for malicious actors to exploit the certificate validation system through carefully crafted HTML content. The flaw specifically targets the X.509 certificate validation process, which is fundamental to establishing secure communications over the internet.
The technical nature of this vulnerability lies in the improper validation of certificate signatures within Chrome's networking infrastructure. When processing X.509 certificates, the browser's certificate handling code fails to perform adequate consistency checks that would normally verify the integrity of certificate signatures. This allows a remote attacker to construct a malicious HTML page that contains a specially crafted X.509 certificate with invalid or malformed signature data. The browser's insufficient validation mechanisms fail to detect these inconsistencies, leading to the acceptance of certificates that should have been rejected based on standard security protocols. This represents a breakdown in the certificate validation chain that undermines the trust model that secure web communications depend upon.
The operational impact of CVE-2017-5066 is significant as it enables man-in-the-middle attacks and certificate forgery scenarios. Attackers can exploit this vulnerability to present fake certificates that appear legitimate to the victim's browser, potentially allowing them to intercept encrypted communications between users and web servers. This weakness can be particularly dangerous in environments where sensitive data is transmitted, as it provides attackers with opportunities to eavesdrop on communications or redirect users to malicious websites without detection. The vulnerability affects all versions of Chrome prior to the specified patch releases, making it a widespread concern across multiple operating systems and device types. The attack vector through crafted HTML pages makes it particularly insidious as users may encounter these malicious certificates while browsing legitimate websites, creating a false sense of security.
This vulnerability maps to CWE-295 which specifically addresses "Improper Certificate Validation" and aligns with ATT&CK technique T1055.011 for "Process Injection" and T1557.001 for "Adversarial Traffic Injection." The flaw creates a pathway for attackers to manipulate certificate validation processes, potentially enabling more sophisticated attacks that leverage the compromised trust model. Organizations should implement immediate patching strategies to address this vulnerability, as the risk of exploitation increases with the prevalence of web-based attacks. The remediation process requires updating Chrome to the patched versions mentioned in the advisory, with additional network monitoring to detect potential exploitation attempts. Security teams should also consider implementing certificate pinning mechanisms and enhanced network traffic analysis to detect anomalous certificate behavior that might indicate exploitation attempts. The vulnerability underscores the critical importance of robust certificate validation processes in maintaining secure communications and highlights the need for continuous security testing of cryptographic implementations within web browsers.