Credit: WordPress / Thinkstock WordPress sites with the plug-in Fancybox-for-WordPress should apply a critical security update released Thursday that fixes a vulnerability already exploited by attackers.Researchers from Web security firm Sucuri issued a warning about the vulnerability Wednesday after seeing attacks that injected a malicious iframe into websites.They tracked down the problem to a flaw in Fancybox-for-WordPress, which allows webmasters to easily integrate the Fancybox JavaScript library into their WordPress sites. FancyBox is a tool for displaying images, HTML content and multimedia in a so-called “lightbox” that floats on top of Web pages.Fancybox-for-WordPress has been downloaded almost 600,000 times from the official WordPress plug-in repository to date. “After some analysis, we can confirm that this plugin has a serious vulnerability that allows for malware (or any random script/content) to be added to the vulnerable site,” the Sucuri researchers said in a blog post in which they advised users to remove the plug-in because the flaw was unpatched.That might no longer be necessary as the plug-in’s developers released two new versions in rapid succession Thursday to fix the vulnerability. Version 3.0.3 addresses the actual flaw, while version 3.0.4 renames the plug-in setting where the issue originated. “This should stop the malicious code from appearing on sites where the plugin is updated without removing the malicious code,” the plug-in developers said in the changelog.Users are advised to update to the latest version — 3.0.4.WordPress sites are a favorite target for hackers, who compromise them to host malicious content and spam pages or to try and gain control of the underlying Web servers. Vulnerabilities in WordPress plug-ins and themes have been exploited before in large scale attacks that compromised thousands of websites. Related content news UK government plans 2,500 new tech recruits by 2025 with focus on cybersecurity New apprenticeships and talent programmes will support recruitment for in-demand roles such as cybersecurity technologists and software developers By Michael Hill Sep 29, 2023 4 mins Education Industry Education Industry Education Industry news UK data regulator orders end to spreadsheet FOI requests after serious data breaches The Information Commissioner’s Office says alternative approaches should be used to publish freedom of information data to mitigate risks to personal information By Michael Hill Sep 29, 2023 3 mins Government Cybercrime Data and Information Security feature Cybersecurity startups to watch for in 2023 These startups are jumping in where most established security vendors have yet to go. By CSO Staff Sep 29, 2023 19 mins CSO and CISO Security news analysis Companies are already feeling the pressure from upcoming US SEC cyber rules New Securities and Exchange Commission cyber incident reporting rules don't kick in until December, but experts say they highlight the need for greater collaboration between CISOs and the C-suite By Cynthia Brumfield Sep 28, 2023 6 mins Regulation Data Breach Financial Services Industry Podcasts Videos Resources Events SUBSCRIBE TO OUR NEWSLETTER From our editors straight to your inbox Get started by entering your email address below. Please enter a valid email address Subscribe