CWE-539 (通过持久性Cookie导致的信息暴露) — Vulnerability Class 6

CWE-539 represents a data exposure weakness where web applications store sensitive information within persistent cookies. These cookies, which remain on the user’s device after the browser closes, are typically exploited by attackers who gain access to the local file system or intercept unencrypted network traffic. By reading these stored values, adversaries can steal session identifiers, authentication tokens, or personally identifiable information, leading to account takeover or privacy breaches. To mitigate this risk, developers must strictly avoid placing any confidential data in cookies. Instead, they should utilize server-side sessions for state management and ensure that any necessary client-side storage contains only non-sensitive, public identifiers. Additionally, implementing secure cookie flags, such as HttpOnly and Secure, further reduces the attack surface by preventing client-side script access and enforcing transmission over encrypted channels.