Deserialization of Untrusted Data Vulnerability in Sitecore CMS and XP
CVE-2019-9874

9.8CRITICAL

Key Information:

Vendor: Sitecore
Status: Experience Platform; Cms
Vendor: CVE Published:; 31 May 2019

Badges

📈 Trended📈 Score: 5,450👾 Exploit Exists🟣 EPSS 33%🦅 CISA Reported

What is CVE-2019-9874?

CVE-2019-9874 is a vulnerability identified in the Sitecore Content Management System (CMS) and Sitecore Experience Platform (XP) that affects versions 7.0 to 7.2 and 7.5 to 8.2. Sitecore is a popular digital experience platform used for managing and delivering content across various channels. This vulnerability pertains to the deserialization of untrusted data in the Sitecore Security Anti-CSRF module, which can be exploited by unauthorized attackers. If successfully exploited, this vulnerability could allow attackers to execute arbitrary code, severely compromising the integrity and security of affected organizations’ systems.

Technical Details

The vulnerability exists in the deserialization process of HTTP POST parameters, specifically the __CSRFTOKEN. An unauthenticated attacker can craft a malicious serialized .NET object and submit it through an HTTP POST request. The Sitecore platform processes this untrusted data without adequate validation, leading to arbitrary code execution on the server. This creates a significant security loophole as it bypasses standard access controls and protections.

Potential Impact of CVE-2019-9874

Arbitrary Code Execution: The most direct impact of this vulnerability is the ability for attackers to execute arbitrary code on the server. This could lead to complete system compromise, allowing for further exploitation and potential takeover of the entire Sitecore instance.
Data Breaches: By gaining unauthorized access through this vulnerability, attackers could potentially access sensitive data stored within the CMS, leading to data breaches that can have severe repercussions for organizations in terms of compliance, financial loss, and reputational damage.
Denial of Service: Exploiting this vulnerability might also allow attackers to launch attacks that could disrupt the availability of the Sitecore application, resulting in a denial-of-service condition that affects users and business operations relying on the platform.

CISA Reported

CISA provides regional cyber and physical services to support security and resilience across the United States. CISA monitor the most dangerious vulnerabilities and have identifed as being exploited but is not known by the CISA to be used in ransomware campaigns. This is subject to change at pace

The CISA's recommendation is: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.