https://feed.craftedsignal.io/tags/protocol-handler/Trending threats, MITRE ATT&CK coverage, and detection metadata. Fed continuously.Hugoenhello@craftedsignal.iohello@craftedsignal.ioFri, 08 May 2026 18:46:04 +0000https://feed.craftedsignal.io/briefs/2024-05-electerm-code-exec/Fri, 08 May 2026 18:46:04 +0000hello@craftedsignal.iohttps://feed.craftedsignal.io/briefs/2024-05-electerm-code-exec/Electerm versions 3.0.6 through 3.8.14 are vulnerable to arbitrary local code execution via crafted electerm:// URIs or command-line arguments, requiring a user to click a malicious link or open a malicious shortcut file.Electerm, a free and open-source terminal/ssh/sftp client, is vulnerable to arbitrary code execution. Versions 3.0.6 through 3.8.14 are susceptible to this vulnerability. An attacker can exploit this by crafting a malicious electerm:// URI or by crafting a shortcut/command that launches electerm with attacker-controlled --opts arguments. Successful exploitation requires a user to click the malicious link or open the malicious shortcut file. This vulnerability allows attackers to execute arbitrary code on the victim’s machine, potentially leading to system compromise, data theft, or other malicious activities. The vulnerability was reported by Curly-Haired-Baboon.

Attack Chain

1. The attacker crafts a malicious electerm:// URI or a shortcut/command containing malicious --opts arguments.
2. The attacker distributes the malicious URI or shortcut/command to the victim via social engineering or other means.
3. The victim clicks on the malicious electerm:// URI or opens the malicious shortcut/command.
4. Electerm is launched with the attacker-controlled parameters.
5. Due to insufficient validation of the input, the attacker’s payload is processed by Electerm.
6. The attacker’s payload executes arbitrary code on the victim’s machine.
7. The attacker gains control of the compromised system, enabling them to perform malicious activities.

Impact

Successful exploitation of this vulnerability can lead to arbitrary code execution on the victim’s machine. This can result in a wide range of malicious activities, including but not limited to, system compromise, data theft, installation of malware, and denial of service. Given the nature of Electerm as a terminal client, attackers could potentially gain access to sensitive credentials and systems managed through the application.

Recommendation

• Upgrade Electerm to version 3.8.15 or later to patch CVE-2026-43944.
• Disable or unregister electerm protocol handlers (Deep Link settings) as a workaround.
• Avoid clicking electerm:// links from untrusted sources.
• Refrain from running electerm with untrusted --opts arguments or opening .lnk / .desktop files from untrusted sources.
• Deploy the Sigma rule “Detect Electerm URI Protocol Handler Abuse” to identify attempts to exploit this vulnerability by monitoring process execution that involves the electerm protocol.

]]>criticaladvisorycode-executionprotocol-handlerelectermhttps://feed.craftedsignal.io/briefs/2024-07-electerm-rce/Wed, 03 Jul 2024 12:00:00 +0000hello@craftedsignal.iohttps://feed.craftedsignal.io/briefs/2024-07-electerm-rce/Electerm versions 3.8.15 and earlier are vulnerable to arbitrary code execution due to improper validation of URLs, allowing attackers to execute commands by tricking users into clicking malicious links in the terminal.Electerm, a cross-platform terminal application, is vulnerable to an arbitrary protocol execution vulnerability (CVE-2026-43941) in versions 3.8.15 and earlier. This flaw stems from the application’s failure to properly validate URLs passed to the shell.openExternal function. An attacker who can control terminal output, such as through a compromised SSH server or a malicious plugin, can inject a crafted URI into the terminal. If a user clicks on this malicious link, Electerm will execute it using the operating system’s default protocol handler, potentially leading to code execution, data exfiltration, or other malicious activities. This vulnerability requires user interaction (clicking the link) to be exploited.

Attack Chain

1. Attacker compromises a remote SSH server or injects malicious content into terminal output.
2. The attacker crafts a malicious URI containing a dangerous protocol handler like ms-msdt:, search-ms:, or file://.
3. The malicious URI is printed to the Electerm terminal connected to the compromised SSH server.
4. The victim, using Electerm, views the terminal output containing the malicious URI.
5. The victim clicks on the malicious URI hyperlink in the Electerm terminal.
6. Electerm’s shell.openExternal function executes the URI without proper validation.
7. The operating system’s default protocol handler is invoked, executing the attacker’s payload (e.g., code execution via ms-msdt:, NTLM hash leak via file://).
8. Attacker achieves arbitrary code execution or exfiltrates sensitive information.

Impact

Successful exploitation of this vulnerability (CVE-2026-43941) could allow an attacker to execute arbitrary code on a victim’s machine. This could lead to complete system compromise, data theft, or the installation of malware. The vulnerability affects all Electerm users who interact with untrusted terminal outputs. The number of potential victims is dependent on Electerm’s user base. If successfully exploited, an attacker gains the privileges of the user running Electerm.

Recommendation

• Deploy the Sigma rule “Detect Electerm Suspicious URI Invocation” to detect attempts to exploit CVE-2026-43941 by monitoring process creations with unusual protocol handlers (see rule definition below).
• Apply the workaround to disable hyperlink rendering in electerm’s terminal settings until a patch is available.
• Monitor the electerm GitHub releases and security page for an update addressing this issue.

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