Vulnerability-Lookup

CVE-2026-49253 (GCVE-0-2026-49253)

Vulnerability from cvelistv5 – Published: 2026-08-19 14:31 – Updated: 2026-08-21 19:31

Title

electerm: Path Traversal in Zmodem and Trzsz Download Filename Handling

Summary

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.

Severity

7.1 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-21 19:31 UTC

CWE

CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7902 records in the last 180 days details

References

3 references

URL	Tags
https://github.com/electerm/electerm/security/adv…	x_refsource_CONFIRM
https://github.com/electerm/electerm/commit/fde15…	x_refsource_MISC
https://github.com/electerm/electerm/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
electerm	electerm	Affected: < 3.11.11	guessed

Show details on NVD website

JSON

To clipboard

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}

FKIE_CVE-2026-49253

Vulnerability from fkie_nvd - Published: 2026-08-19 15:17 - Updated: 2026-10-27 13:10

Severity

7.1 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/electerm/electerm/commit/fde153d677a170c5816368f6586647f3af4ef284
	security-advisories@github.com	https://github.com/electerm/electerm/releases/tag/v3.11.11
	security-advisories@github.com	https://github.com/electerm/electerm/security/advisories/GHSA-38j7-23hf-9mhc
	134c704f-9b21-4f2e-91b3-4a467353bcc0	https://github.com/electerm/electerm/security/advisories/GHSA-38j7-23hf-9mhc

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "electerm",
          "vendor": "electerm",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 3.11.11"
            }
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    },
    {
      "lang": "es",
      "value": "electerm es un cliente de terminal/ssh/sftp/telnet/puerto serie/RDP/VNC/Spice/ftp de c\u00f3digo abierto. Antes de la versi\u00f3n 3.11.11, electerm utiliza nombres de archivo proporcionados remotamente directamente con path.join() al recibir transferencias Zmodem y Trzsz. En src/app/server/zmodem.js, prepareReceiveFile() une el nombre de archivo a la ruta de guardado seleccionada por el usuario, y en src/app/server/trzsz.js, getUniqueFilePath(), la devoluci\u00f3n de llamada openSaveFile() y la asignaci\u00f3n savedFilePaths construyen destinos sin saneamiento. Un servidor SSH malicioso o shell remoto puede proporcionar un nombre de archivo que contiene componentes de recorrido como .. / escaped.txt o .. / .. / .bashrc. Cuando la v\u00edctima acepta la transferencia y selecciona un directorio de descarga, electerm puede escribir fuera de ese directorio y sobrescribir archivos accesibles para el usuario de escritorio, potencialmente cambiando la configuraci\u00f3n sensible o afectando la disponibilidad. Este problema est\u00e1 solucionado en la versi\u00f3n 3.11.11."
    }
  ],
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}

GHSA-38J7-23HF-9MHC

Vulnerability from github – Published: 2026-07-02 19:20 – Updated: 2026-07-02 19:20

Summary

electerm has Path Traversal in Zmodem and Trzsz Download Filename Handling

Details

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: 1. User connects to a malicious SSH server 2. Attacker initiates a Zmodem or Trzsz file transfer 3. Attacker supplies a traversal filename (e.g., ../../.bashrc, ../escaped.txt) 4. User accepts the transfer and selects a download directory 5. File is written outside the selected directory, potentially overwriting sensitive files

Affected components: - src/app/server/zmodem.js - prepareReceiveFile() at line 736 - src/app/server/trzsz.js - getUniqueFilePath() at line 559, openSaveFile() callback, and savedFilePaths mapping

Patches

https://github.com/electerm/electerm/commit/fde153d677a170c5816368f6586647f3af4ef284

Workarounds

If upgrading is not immediately possible, users can mitigate this vulnerability by: 1. Only connecting to trusted SSH servers 2. Rejecting or canceling any incoming Zmodem or Trzsz file transfers from untrusted sources 3. Avoiding the use of Zmodem (sz/rz) and Trzsz (trz/tsz) commands on untrusted servers

Severity

7.1 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 3.11.0"
      },
      "package": {
        "ecosystem": "npm",
        "name": "electerm"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.11.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-49253"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-22"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-02T19:20:20Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Impact\n\nA 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.\n\nA 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\u0027s filesystem, subject to process permissions.\n\n**Attack scenario:**\n1. User connects to a malicious SSH server\n2. Attacker initiates a Zmodem or Trzsz file transfer\n3. Attacker supplies a traversal filename (e.g., `../../.bashrc`, `../escaped.txt`)\n4. User accepts the transfer and selects a download directory\n5. File is written outside the selected directory, potentially overwriting sensitive files\n\n**Affected components:**\n- `src/app/server/zmodem.js` - `prepareReceiveFile()` at line 736\n- `src/app/server/trzsz.js` - `getUniqueFilePath()` at line 559, `openSaveFile()` callback, and `savedFilePaths` mapping\n\n### Patches\n\n- https://github.com/electerm/electerm/commit/fde153d677a170c5816368f6586647f3af4ef284\n\n### Workarounds\n\n\nIf upgrading is not immediately possible, users can mitigate this vulnerability by:\n1. Only connecting to trusted SSH servers\n2. Rejecting or canceling any incoming Zmodem or Trzsz file transfers from untrusted sources\n3. Avoiding the use of Zmodem (`sz`/`rz`) and Trzsz (`trz`/`tsz`) commands on untrusted servers",
  "id": "GHSA-38j7-23hf-9mhc",
  "modified": "2026-07-02T19:20:20Z",
  "published": "2026-07-02T19:20:20Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/electerm/electerm/security/advisories/GHSA-38j7-23hf-9mhc"
    },
    {
      "type": "WEB",
      "url": "https://github.com/electerm/electerm/commit/fde153d677a170c5816368f6586647f3af4ef284"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/electerm/electerm"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "electerm has Path Traversal in Zmodem and Trzsz Download Filename Handling"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

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How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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Action not permitted

CVE-2026-49253 (GCVE-0-2026-49253)

FKIE_CVE-2026-49253

GHSA-38J7-23HF-9MHC

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