CVE-2022-2860 is a vulnerability identified in Google Chrome versions prior to 104.0.5112.101, involving insufficient policy enforcement related to cookie prefixes. Specifically, Chrome failed to properly enforce restrictions on cookies that use certain prefixes, such as '__Host-' and '__Secure-', which are intended to provide additional security guarantees by restricting cookie scope and transmission. An attacker can exploit this vulnerability by crafting a malicious HTML page that bypasses these cookie prefix restrictions, potentially allowing them to set or manipulate cookies in ways that violate the intended security policies. This could lead to unauthorized modification of cookie data, which may impact the integrity of user sessions or application state. The vulnerability has a CVSS 3.1 base score of 6.5, indicating a medium severity level. The vector indicates that the attack can be performed remotely over the network (AV:N), requires low attack complexity (AC:L), no privileges (PR:N), but requires user interaction (UI:R). The impact is limited to integrity (I:H), with no confidentiality or availability impact. There are no known exploits in the wild reported at the time of publication. The vulnerability was publicly disclosed on September 26, 2022, and affects unspecified versions prior to Chrome 104.0.5112.101. The root cause is a failure in enforcing cookie prefix policies, which are critical for securing cookies against cross-site scripting and other web-based attacks. This flaw could be leveraged by attackers to bypass security controls that rely on cookie prefix enforcement, potentially facilitating session fixation or other cookie-based attacks.

For European organizations, this vulnerability poses a moderate risk primarily to web applications and services accessed via vulnerable Chrome browsers. Since Chrome is widely used across Europe, the potential for exploitation exists wherever users visit malicious or compromised websites that host crafted HTML pages exploiting this flaw. The main impact is on the integrity of cookie data, which could lead to session manipulation or unauthorized actions within web applications. This may result in unauthorized access to user accounts or manipulation of user sessions, potentially leading to data tampering or fraud. However, there is no direct impact on confidentiality or availability, and exploitation requires user interaction (visiting a malicious page). Organizations in sectors with high reliance on web applications, such as finance, e-commerce, and government services, may face increased risk if attackers use this vulnerability as part of a broader attack chain. The lack of known exploits in the wild reduces immediate threat but does not eliminate the risk, especially if attackers develop new exploits. Compliance with GDPR and other data protection regulations may be impacted if session integrity is compromised leading to unauthorized data processing or access.

European organizations should ensure that all Chrome browsers are updated to version 104.0.5112.101 or later, where this vulnerability has been patched. Beyond patching, organizations should implement Content Security Policy (CSP) headers to restrict the sources of executable scripts and reduce the risk of malicious HTML injection. Web application developers should validate and sanitize all inputs rigorously to prevent injection of malicious content that could exploit cookie handling. Additionally, organizations should monitor web traffic for unusual cookie-setting behavior and consider deploying browser security extensions or endpoint protection solutions that can detect and block suspicious web content. User awareness training is important to reduce the risk of users visiting malicious sites. For critical internal applications, consider enforcing strict cookie attributes (HttpOnly, Secure, SameSite) and server-side session management to reduce reliance on client-side cookie security. Finally, organizations should maintain an inventory of browser versions in use and enforce update policies to minimize exposure.