Citrix 'Recording Manager' Zero-Day Bug Allows Unauthenticated RCE

The security vulnerability is due to an exposed Microsoft Message Queuing (MSMQ) instance and the use of the insecure BinaryFormatter.

Thief in ski mask running away with laptop
Source: Brian Jackson via Alamy Stock PhotoSource:

[Ed. note, Nov. 12 at 12:30 p.m. ET: Citrix has now issued patches for the issue and assigned CVE-2024-8068/CVE-2024-8069 for tracking.]

An unpatched zero-day vulnerability in Citrix’s Session Recording Manager allows unauthenticated remote code execution (RCE, paving the way for data theft, lateral movement, and desktop takeover.

According to watchTowr research out today, the issue (which does not yet have a CVE or CVSS score) resides in Citrix's Session Recording Manager, which, as its name implies, records user activity, including keyboard and mouse inputs, websites visited, video streams of desktop activity, and more.

"Citrix advertises the feature as being really useful for monitoring (somewhat obviously), but also for compliance and troubleshooting. It can even be set up so that certain actions (like identifying sensitive data) will trigger recording, which helps meet regulatory needs and flag suspicious activities," the watchTowr researchers noted in the report.

The feature logs session recordings via Microsoft Message Queuing (MSMQ), which enables efficient data transfer from individual computers to centralized storage. However, the Citrix implementation uses BinaryFormatter for serialization and deserialization of the information for easier and more accurate transfer and storage. The utility is unfortunately well-known to be insecure.

Related:Russia's 'BlueAlpha' APT Hides in Cloudflare Tunnels

BinaryFormatter is a .NET class created by Microsoft, which is in the process of deprecating it: "BinaryFormatter is insecure and can't be made secure. Applications should stop using [it] as soon as possible, even if they believe the data they're processing to be trustworthy," the computing giant said in August.

On top of the BinaryFormatter issue, Recording Session Manager also involves an exposed MSMQ service that can be reached from any host via HTTP. This, combined with what watchTowr says are misconfigured permissions, paves the way for unauthenticated RCE.

Dark Reading has reached out for comment and planned patching or mitigation information from both watchTowr and Citrix. There is no evidence of in-the-wild exploitation yet, but given Citrix's attractiveness as a cybercrime target, that could soon change.

Don't miss the upcoming free Dark Reading Virtual Event, "Know Your Enemy: Understanding Cybercriminals and Nation-State Threat Actors," Nov. 14 at 11 am ET. Don't miss sessions on understanding MITRE ATT&CK, using proactive security as a weapon, and a masterclass in incident response; and a host of top speakers like Larry Larson from the Navy Credit Federal Union, former Kaspersky Lab analyst Costin Raiu, Ben Read of Mandiant Intelligence, Rob Lee from SANS, and Elvia Finalle from Omdia. Register now!

Related:News Desk 2024: The Rise of Cybersecurity Platforms

About the Author

Tara Seals, Managing Editor, News, Dark Reading

Tara Seals has 20+ years of experience as a journalist, analyst and editor in the cybersecurity, communications and technology space. Prior to Dark Reading, Tara was Editor in Chief at Threatpost, and prior to that, the North American news lead for Infosecurity Magazine. She also spent 13 years working for Informa (formerly Virgo Publishing), as executive editor and editor-in-chief at publications focused on both the service provider and the enterprise arenas. A Texas native, she holds a B.A. from Columbia University, lives in Western Massachusetts with her family and is on a never-ending quest for good Mexican food in the Northeast.

Keep up with the latest cybersecurity threats, newly discovered vulnerabilities, data breach information, and emerging trends. Delivered daily or weekly right to your email inbox.

You May Also Like


More Insights