**CRITICAL RISK** CVE-2023-29300 Adobe ColdFusion (2018, 2021, 2023) – Arbitrary Code Execution via Unsafe Deserialisation of Untrusted Data

Background & Context

Adobe ColdFusion is a commercial rapid web-application development computing platform (the programming language used with that platform is also commonly called ColdFusion, though is more accurately known as CFML.) ColdFusion includes an IDE in addition to a full scripting language. One of the distinguishing features of ColdFusion is its associated scripting language, ColdFusion Markup Language (CFML). CFML compares to the scripting components of ASP, JSP, and PHP in purpose and features, but its tag syntax more closely resembles HTML, while its script syntax resembles JavaScript. ColdFusion is often used synonymously with CFML, but there are additional CFML application servers besides ColdFusion, and ColdFusion supports programming languages other than CFML, such as server-side ActionScript and embedded scripts that can be written in a JavaScript-like language known as CFScript.

ColdFusion is most often used for data-driven websites or intranets, but can also be used to generate remote services such as REST services, WebSockets, SOAP web services or Flash remoting. It is especially well-suited as the server-side technology to the client-side ajax. ColdFusion can also handle asynchronous events such as SMS and instant messaging via its gateway interface, available in ColdFusion MX 7 Enterprise Edition.

 

Vulnerability Summary

Multiple versions of Adobe ColdFusion are affected by a Deserialization of Untrusted Data vulnerability. Exploitation of this issue does not require user interaction.

It is often convenient to serialize objects for communication or to save them for later use. However, deserialized data or code can often be modified without using the provided accessor functions if it does not use cryptography to protect itself. Furthermore, any cryptography would still be client-side security — which is a dangerous security assumption. Data that is untrusted can not be trusted to be well-formed.

On July 11, 2023, Adobe released security updates for ColdFusion versions  2023, 2021 and  2018 containing fixes for three vulnerabilities (CVE-2023-29298, CVE-2023-29300, and CVE-2023-29301). However, the patch for CVE-2023-29300 was technically incomplete: Adobe prohibited the deserialization of Web Distributed Data eXchange data, but used an incomplete denylist of Java class paths, meaning that the vulnerability can still be exploited.

 

Impact If Exploited

When developers place no restrictions on “gadget chains,” or series of instances and method invocations that can self-execute during the deserialization process (i.e., before the object is returned to the caller), it is sometimes possible for attackers to leverage them to perform unauthorized actions, like generating a shell.

Exploit could result in Arbitrary code execution.

NOTE: This vulnerability has been reported by the CISA (America’s Cyber Defense Agency) to be known to be currently actively exploited in the wild as of 2024-01-08. Prioritisation should be given to remediation in any impacted environment

 

Affected Product Versions

  • Adobe ColdFusion version 2018u16 (and earlier)
  • Adobe ColdFusion version 2021u6 (and earlier)
  • Adobe ColdFusion version 2023.0.0.330468 (and earlier)

 

Remediation

Official Fix & Remediation Guidance

In the out-of-band patch for CVE-2023-38203, Adobe added one more class path [[code:!com.sun.rowset.**]] to the denylist.

Customers are advised to upgrade to the latest version of Adobe ColdFusion.

NOTE: Remediation of this vulnerability by patching to a specific version indicated may not be sufficient to secure the product against further vulnerabilities discovered in later versions, subsequent to the publication of this guidance. Unless contra-indicated, customers are therefore advised to always upgrade to the latest version of the product available.

 

Temporary Mitigation & Workarounds:

(The vendor has not advised of any alternative temporary mitigation or workarounds)

NOTE: Caution should always be taken in applying any temporary mitigations listed. Mitigations are only recommended in cases where patches to remediate the vulnerability are not available, or cannot safely be applied to a given environment immediately. A given mitigation may not in all cases be recommended officially by the application vendor. The viability of any given temporary mitigation measure may vary, depending on server platform and existing configuration. Mitigations listed may incompletely remediate any given vulnerability. Configuration changes to implement listed mitigations may impact/disrupt required functionality within a given customer application. Care should therefore be taken to carefully analyse any listed mitigations for appropriateness to a given environment. Customers are advised to test any configuration changes prior to their being introduced into a production environment.

 

References:

 

Category: Deserialization of Untrusted Data

 

Detection

AppCheck has added a plugin to detect the flaw that will run as part of your standard scans.

 

About AppCheck

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