#VU17273 Deserialization of Untrusted Data in Yasr – Yet Another Stars Rating

Vulnerability identifier: #VU17273

Vulnerability risk: High

CVSSv4.0: 8.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Amber]

CVE-ID: N/A

CWE-ID: CWE-502

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Yasr – Yet Another Stars Rating
Web applications / Modules and components for CMS

Vendor: Dario Curvino

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to insecure input validation when processing serialized data with unserializae() function in "/lib/yasr-functions.php" file. A remote attacker can pass specially crafted data via HTTP cookie to the application and execute arbitrary PHP code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Yasr – Yet Another Stars Rating: 1.6.2 - 1.8.6

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External links
https://dannewitz.ninja/posts/php-unserialize-object-injection-yet-another-stars-rating-wordpress

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.