In the vast landscape of WordPress plugins, one name stands out: 'Gravity Forms.' This premium plugin has earned its reputation as a go-to tool for over 930,000 websites. However, a recent revelation has uncovered a large vulnerability — certain versions Gravity Forms is alarmingly vulnerable to unauthenticated PHP object injection.
Designed as a versatile custom form builder, Gravity Forms enables website owners to effortlessly create an array of essential forms. Whether it's a payment form, registration form, file upload form, or any other interactive element crucial for visitor-site interactions or transactions, Gravity Forms has been a reliable tool for countless online ventures.
Gravity Forms proudly claims that it is used by a large variety of well-known companies such as Airbnb, ESPN, NASA, Nike and Unicef.
A crucial vulnerability, tracked as CVE-2023-28782, affects all versions of the Gravity Forms Plugin up to 2.73.
On March 27th, 2023, security researchers at PatchStack uncovered a significant flaw in the Gravity Forms plugin. However, the diligent efforts of the vendor resulted in a prompt resolution with the release of version 2.7.4 on April 11th, 2023.
To safeguard their websites, administrators utilising Gravity Forms are strongly urged to promptly implement the provided security update.
Vulnerability specifics
The problem stems from the absence of proper input validation checks within the 'maybe_unserialize' function, which can be exploited by submitting data through a Gravity Forms-created form.
According to PatchStack's report, this vulnerability takes advantage of PHP's object serialization capability, enabling an unauthorised user to inject arbitrary PHP object(s) into the application's scope through a susceptible unserialize call. It is important to note that this vulnerability can be triggered even on a default installation or configuration of the Gravity Forms plugin, requiring only a created form that includes a list field.
In spite of the potential impact of CVE-2023-28782, PatchStack's analysts were unable to uncover a notable POP (property-oriented programming) chain within the affected plugin, partially reducing the risk.
Nevertheless, the risk remains substantial in cases where the same website utilises other plugins or themes that do contain a POP chain. This scenario is not uncommon, considering the extensive selection of WordPress plugins and themes available, along with the varying degrees of code quality and security awareness among developers.
In such scenarios, the exploitation of CVE-2023-28782 has the potential to result in unauthorised access and manipulation of files, extraction of user/member data, execution of malicious code, and other detrimental consequences.
To address this flaw, the plugin vendor rectified the situation by eliminating the usage of the 'maybe_unserialize' function in version 2.74 of the Gravity Forms plugin.
Additionally, it is crucial to ensure that all active plugins and themes on your WordPress site are kept up to date. By applying necessary updates, you can effectively eliminate potential attack vectors, such as POP chains, that could be exploited to launch harmful attacks in this particular case.
How can we help?
When it comes to safeguarding your online presence against critical vulnerabilities like CVE-2023-28782, proactive measures are essential. With our specialised services, such as web application penetration testing, we can assist in identifying and mitigating potential risks.
By leveraging our expertise and advanced techniques, businesses can gain valuable insights into their security posture. Through rigorous testing, vulnerabilities can be uncovered, allowing for timely remediation and fortification of web applications against potential attacks.
In an ever-evolving cyber security landscape, partnering with a trusted organisation ensures that your systems are thoroughly assessed, vulnerabilities are identified, and robust defences are implemented. By prioritising security and staying vigilant against emerging threats, businesses can instil confidence in their online operations and protect their valuable assets.
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