The premium WordPress plugin ‘Gravity Forms,’ widely utilized by over 930,000 websites, has been found to have a vulnerability that allows unauthenticated PHP Object Injection. The flaw, tracked as CVE-2023-28782, affects all plugin versions from 2.73 and below.
The issue was discovered by PatchStack and promptly fixed by the plugin vendor through the release of version 2.7.4. Website administrators using Gravity Forms are strongly advised to update to the latest version to mitigate the risk of potential attacks, such as arbitrary code execution and unauthorized file access.
The vulnerability stems from a lack of user-supplied input checks for the ‘maybe_unserialize’ function within Gravity Forms. An attacker can exploit this vulnerability by submitting manipulated data through a form created with the plugin.
Although PatchStack’s analysts did not find a significant POP (property-oriented programming) chain within the plugin itself, the risk becomes more severe if the affected site also utilizes other plugins or themes that contain such chains, which is not uncommon in the WordPress ecosystem.
The consequences of exploiting CVE-2023-28782 can include unauthorized access and modification of files, exfiltration of user/member data, and code execution. The plugin vendor addressed the flaw by removing the ‘maybe_unserialize’ function from Gravity Forms in version 2.74.
To ensure comprehensive security, it is crucial for website administrators to update not only the Gravity Forms plugin but also all active plugins and themes on their WordPress sites.
By applying security fixes, potential attack vectors, including POP chains, can be eliminated, thereby reducing the risk of damaging exploits.
