In breve
- CVE-2026-49253 è una vulnerabilità ALTO (CVSS 7.1) che riguarda electerm.
- Probabilità di sfruttamento nei prossimi 30 giorni (EPSS): 0.44%, superiore al 38.2% delle vulnerabilità.
- Correzione: aggiornare a 3.11.11 o successiva.
| Package | Affected versions | Patched versions |
|---|
| electerm npm | < 3.11.11
| 3.11.11
|
Description
Impact
A path traversal vulnerability exists in the Zmodem and Trzsz file download handlers in electerm. When receiving files via Zmodem or Trzsz protocols, electerm uses the remote-supplied filename directly in path.join() with the user-selected download directory without sanitization.
A malicious SSH server or remote shell process can send a specially crafted filename such as ../escaped.txt to escape the user-selected download directory and write files to arbitrary locations on the user's filesystem, subject to process permissions.
Attack scenario:
- User connects to a malicious SSH server
- Attacker initiates a Zmodem or Trzsz file transfer
- Attacker supplies a traversal filename (e.g.,
../../.bashrc, ../escaped.txt)
- User accepts the transfer and selects a download directory
- File is written outside the selected directory, potentially overwriting sensitive files
Affected components:
src/app/server/zmodem.js - prepareReceiveFile() at line 736src/app/server/trzsz.js - getUniqueFilePath() at line 559, openSaveFile() callback, and savedFilePaths mapping
Patches
Workarounds
If upgrading is not immediately possible, users can mitigate this vulnerability by:
- Only connecting to trusted SSH servers
- Rejecting or canceling any incoming Zmodem or Trzsz file transfers from untrusted sources
- Avoiding the use of Zmodem (
sz/rz) and Trzsz (trz/tsz) commands on untrusted servers
NVD description
electerm is an open-sourced terminal/ssh/sftp/telnet/serialport/RDP/VNC/Spice/ftp client. Prior to 3.11.11, electerm uses remote-supplied filenames directly with path.join() while receiving Zmodem and Trzsz transfers. In src/app/server/zmodem.js, prepareReceiveFile() joins the filename to the user-selected save path, and in src/app/server/trzsz.js, getUniqueFilePath(), the openSaveFile() callback, and the savedFilePaths mapping construct destinations without sanitization. A malicious SSH server or remote shell can provide a filename containing traversal components such as ../escaped.txt or ../../.bashrc. When the victim accepts the transfer and selects a download directory, electerm can write outside that directory and overwrite files accessible to the desktop user, potentially changing sensitive configuration or impairing availability. This issue is fixed in version 3.11.11.
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