A critical SQL injection vulnerability in a WordPress plugin with 200,000 installations could be exploited to extract sensitive data, according to a wording from security vendor Defiant.
The flaw, tracked as CVE-2024-1071 (CVSS score of 9.8), affects web sites running the Ultimate Member WordPress membership plugin and could be exploited by unauthenticated attackers to append SQL queries to existing ones and extract information from databases.
According to Defiant, the bug exists because of an insecure implementation in users query functionality, which results in the text sanitization function failing to protect against SQL injection attacks.
The company’s researchers also found that that the structure of the query only allows attackers to take a time-based blind approach, using SQL CASE statements and the sleep command while observing the response time for the requests to steal information.
“This is an intricate, yet frequently successful method to obtain information from a database when exploiting SQL Injection vulnerabilities,” Defiant said in an advisory. However, the vulnerability can only be exploited if the plugin’s “Enable custom table for usermeta” option is active.
“This means that not all users running the plugin would be inherently vulnerable, but nonetheless we recommend updating immediately as attackers are clever and could chain vulnerabilities in plugins to achieve a complete site takeover,” Defiant notes.
Reported on January 30, the vulnerability was resolved on February 19, in Ultimate Member version 2.8.3. The reporting researcher received a $2,063 bug bounty reward for the finding.
Ultimate Member users are advised to update to the patched version as soon as possible. Defiant says it has already blocked one attempt to exploit the bug.
With over 200,000 active installations, Ultimate Member is a user profile and membership plugin allowing WordPress site administrators to manage user registration, logins, profiles, and roles.
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