CVE-2026-123014 in iTerm2
Summary
by MITRE • 11/05/2026
iTerm2 before 3.7.7beta2 has an argument injection vulnerability in the x-man-page: URL handler, allowing an attacker to execute arbitrary commands with the privileges of the logged-in user by inducing the user to open a crafted URL in iTerm2. Percent-encoded NUL characters survive input sanitization and are subsequently converted to whitespace during command-line parsing, allowing injection of additional arguments to /usr/bin/man. An attacker can inject the -P option to select an attacker-controlled pager command. NOTE: this issue exists because of an incomplete fix for CVE-2023-46321.
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Analysis
by VulDB Data Team • 11/05/2026
The vulnerability identified in iTerm2 versions prior to 3.7.7beta2 represents a critical argument injection flaw within the x-man-page URL handler, which serves as a mechanism for launching manual pages directly from browser links or other applications. This security defect allows an attacker to execute arbitrary commands with the privileges of the currently logged-in user by inducing them to open a specifically crafted URL within the iTerm2 terminal emulator. The root cause lies in incomplete input sanitization during the processing of percent-encoded characters, where NUL bytes are not properly stripped or handled before being passed to underlying system utilities.
During the command-line parsing phase, these surviving percent-encoded NUL characters are converted into whitespace separators. This transformation effectively breaks the intended argument structure for the /usr/bin/man utility, allowing an attacker to inject additional arguments that were originally intended to be part of a single string or ignored due to encoding rules. Specifically, by injecting the -P option, which is used to specify the pager command for man pages, an adversary can override the default behavior and force the execution of any arbitrary program defined in their payload. This technique leverages the trust relationship between the terminal emulator and the user's shell environment to escalate from a simple URL click to full remote code execution under the context of the victim account.
The operational impact of this vulnerability is severe, as it facilitates unauthorized command execution without requiring authentication or privilege escalation beyond what the user already possesses. An attacker could potentially install malware, exfiltrate sensitive data, pivot within a network, or establish persistence mechanisms by crafting malicious URLs that are distributed via phishing campaigns, compromised websites, or social engineering vectors. The existence of this flaw is particularly concerning because it indicates an incomplete remediation for CVE-2023-46321, suggesting that previous security patches failed to fully address the underlying input validation logic in the URL handler component.
From a classification perspective, this vulnerability aligns with CWE-78 Improper Neutralization of Special Elements used in an OS Command and CWE-94 Improper Control of Generation of Code. In terms of tactical behavior, it maps to ATT&CK technique T1059 Command and Scripting Interpreter, specifically through the use of shell commands initiated via a user interface interaction such as clicking a link. The attack vector is primarily remote but requires user interaction, placing it in the context of social engineering or drive-by exploitation scenarios where trust in the source of a URL is exploited.
Mitigation strategies must prioritize immediate software updates to version 3.7.7beta2 or later, which addresses the input sanitization flaws regarding NUL character handling and argument parsing logic. Organizations should enforce strict update policies for development tools and terminal emulators used by engineering staff who are frequent targets of such attacks. Additionally, security awareness training is essential to educate users about the risks of opening URLs from untrusted sources within interactive applications that have shell access capabilities. Implementing application whitelisting or restricting the execution of certain system utilities like /usr/bin/man in restricted environments can also reduce the blast radius if a user inadvertently triggers such a payload. Monitoring for unusual child processes spawned by terminal emulators may provide early detection signals for attempted exploitation activities.