Security Experts:

WordPress 4.5.3 Patches Several Vulnerabilities

A WordPress security and maintenance update released this week addresses a total of eight vulnerabilities identified by external researchers and members of the WordPress security team.

The vulnerabilities patched with the release of WordPress 4.5.3 affect versions 4.5.2 and earlier. They have the following descriptions:

  • Yassine Aboukir reported a redirect bypass in the customizer;
  • Jouko Pynnönen and Divyesh Prajapati reported two different cross-site scripting (XSS) flaws related to attachment names;
  • John Blackbourn from the WordPress security team and the Wordfence Research Team independently reported a revision history information disclosure issue;
  • Jennifer Dodd from Automattic reported an embedded denial-of-service (DoS);
  • David Herrera from Alley Interactive reported an issue related to unauthorized category removal from a post;
  • Michael Adams from the WordPress security team found an issue that allows password changes via stolen cookies;
  • Peter Westwood of the WordPress security team reported some less secure sanitize_file_name edge cases.

Jouko Pynnönen told SecurityWeek that the flaw he reported is a stored XSS that allows a low-level user to inject JavaScript in attachment file names. The researcher discovered the issue in mid-May while looking for ways to exploit an authentication-related bug on Uber’s WordPress websites.

“Exploiting the bug isn't possible without first having access to a lower-level account. In other words, the attacker needs login access, either legitimate or via another bug,” Pynnonen said in an email. “Additionally, the attack requires an administrator to view a certain part of the WordPress Dashboard - the list of attachments. The injected script won't be triggered otherwise.”

The expert recently earned $10,000 from Uber after informing the company about a critical authentication bypass vulnerability affecting a third-party plugin used on Uber’s WordPress websites. The WordPress XSS was reported to both Uber and Automattic via their HackerOne bug bounty programs, but neither has decided if the issue qualifies for a reward.

In a blog post published on Tuesday, the Wordfence Research Team said the high severity vulnerability it discovered allows an attacker to gain access to password-protected posts.

On websites with open registration, the vulnerability can be exploited by an anonymous attacker, but on sites where registration is closed, the attacker requires some privileges in order to exploit the flaw. The security hole was reported to the WordPress core team on May 3.

Related: Hacked WordPress Sites Target Random Users

Related: C99 Webshell Increasingly Used in WordPress Attacks

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Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.