Critical RCE Vulnerability Discovered in Popular Cobalt Strike Hacking Software
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2022-39197 | XSS in Fortra Cobalt Strike Teamserver Enables Remote Code Execution Fortra Cobalt Strike's Teamserver fails to properly validate the username field in a Beacon's configuration (CWE-20), producing a cross-site scripting flaw (CWE-79). An attacker who has already compromised a machine running a Cobalt Strike beacon can set a malformed username in the beacon configuration, and the injected content executes when it is rendered in the Teamserver, which the vendor notes can be escalated to executing code remotely on the Teamserver. Code execution on the Teamserver hands the attacker control of the C2 infrastructure itself, including beacon configurations, operator sessions, and the credentials and tooling managed there. Any organization running Fortra Cobalt Strike is affected, with risk highest where an operator is actively interacting with a Teamserver that has beacons from potentially compromised hosts. The flaw is already listed in CISA's Known Exploited Vulnerabilities catalog (added 2023-03-30), carries a high EPSS score of about 46%, and no public proof-of-concept is recorded in the source data. Do: Apply Fortra's updated Cobalt Strike release as soon as possible, per the CISA KEV required action to apply updates per vendor instructions. Because triggering the flaw presupposes an existing beacon foothold, hunt for and evict active beacons in the environment and be cautious rendering content from untrusted beacons in the Teamserver UI. Confirm the team server is running the patched build before treating the finding as remediated. | 6.1 | 46% | KEV |
| largetens of thousands of internet-exposed Cobalt Strike Team servers (roughly 20,000-50,000 per public scans), with total deployments likely higher | |
| CVE-2022-42948 | HTML Injection RCE in Fortra (HelpSystems) Cobalt Strike UI Fortra (formerly HelpSystems) Cobalt Strike 4.7.1 fails to properly escape HTML tags when they are rendered in the Swing components of its user interface, an improper-escaping flaw (CWE-116). An attacker who can cause crafted HTML — for example, content delivered through beacon or team-server data and displayed in the console — to appear in the UI can trigger remote code execution in the Cobalt Strike client, consistent with the CVSS 3.1 score of 9.8 (network vector, low complexity, no privileges or user interaction required). Successful exploitation yields code execution on the machine running the Cobalt Strike UI, typically the operator's workstation, potentially exposing the attacker's or red teamer's tooling, active C2 sessions, and any environments they are connected to. Anyone running the affected release is exposed, including users of unlicensed/copied installations, which are widespread in both legitimate and criminal use of this tool. The bug is listed in CISA's Known Exploited Vulnerabilities catalog (added 2023-03-30, with press reports linking its exploitation to commercial surveillance spyware), carries an EPSS of about 2.7%, and no public PoC is known; one related headline notes the vendor's patch initially fell short, so defenders should verify they are running a fully fixed build. Do: Apply updates per Fortra/HelpSystems instructions (the CISA KEV required action) and confirm the running Cobalt Strike client and team server are on a build with the complete HTML-escaping fix, since the vendor's first patch reportedly fell short. Until patched, treat UI-rendered beacon and event content as untrusted input and limit team-server exposure to untrusted networks. | 9.8 | 3% | KEV |
| moderate≈ thousands of internet-exposed Cobalt Strike team servers and tens of thousands of practitioner users |
Full article422 words · extracted from thehackernews.com · click to collapse
Ravie LakshmananOct 18, 2022
HelpSystems, the company behind the Cobalt Strike software platform, has released an out-of-band security update to address a remote code execution vulnerability that could allow an attacker to take control of targeted systems.
Cobalt Strike is a commercial red-team framework that's mainly used for adversary simulation, but cracked versions of the software have been actively abused by ransomware operators and espionage-focused advanced persistent threat (APT) groups alike.
The post-exploitation tool consists of a team server, which functions as a command-and-control (C2) component, and a beacon, the default malware used to create a connection to the team server and drop next-stage payloads.
The issue, tracked as CVE-2022-42948, affects Cobalt Strike version 4.7.1, and stems from an incomplete patch released on September 20, 2022, to rectify a cross-site scripting (XSS) vulnerability (CVE-2022-39197) that could lead to remote code execution.
"The XSS vulnerability could be triggered by manipulating some client-side UI input fields, by simulating a Cobalt Strike implant check-in or by hooking a Cobalt Strike implant running on a host," IBM X-Force researchers Rio Sherri and Ruben Boonen said in a write-up.
However, it was found that remote code execution could be triggered in specific cases using the Java Swing framework, the graphical user interface toolkit that's used to design Cobalt Strike.
"Certain components within Java Swing will automatically interpret any text as HTML content if it starts with <html>," Greg Darwin, software development manager at HelpSystems, explained in a post. "Disabling automatic parsing of HTML tags across the entire client was enough to mitigate this behavior."
This means that a malicious actor could exploit this behavior by means of an HTML <object> tag, utilizing it to load a custom payload hosted on a remote server and inject it within the note field as well as the graphical file explorer menu in the Cobalt strike UI.
"It should be noted here that this is a very powerful exploitation primitive," IBM researchers said, adding it could be used to "construct a fully featured cross-platform payload that would be able to execute code on the user's machine regardless of the operating system flavor or architecture."
The findings come a little over a week after the U.S. Department of Health and Human Services (HHS) cautioned of the continued weaponization of legitimate tools such as Cobalt Strike in attacks aimed at the healthcare sector.
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