Vulnerability-Lookup

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"
}

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 mitre root

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
electerm	electerm	Affected: < 3.11.11

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JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-49253",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-21T19:31:22.919563Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-21T19:31:45.169Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/electerm/electerm/security/advisories/GHSA-38j7-23hf-9mhc"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "electerm",
          "vendor": "electerm",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 3.11.11"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-22",
              "description": "CWE-22: Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-19T14:31:55.683Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/electerm/electerm/security/advisories/GHSA-38j7-23hf-9mhc",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/electerm/electerm/security/advisories/GHSA-38j7-23hf-9mhc"
        },
        {
          "name": "https://github.com/electerm/electerm/commit/fde153d677a170c5816368f6586647f3af4ef284",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/electerm/electerm/commit/fde153d677a170c5816368f6586647f3af4ef284"
        },
        {
          "name": "https://github.com/electerm/electerm/releases/tag/v3.11.11",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/electerm/electerm/releases/tag/v3.11.11"
        }
      ],
      "source": {
        "advisory": "GHSA-38j7-23hf-9mhc",
        "discovery": "UNKNOWN"
      },
      "title": "electerm: Path Traversal in Zmodem and Trzsz Download Filename Handling"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-49253",
    "datePublished": "2026-08-19T14:31:55.683Z",
    "dateReserved": "2026-05-28T14:33:01.179Z",
    "dateUpdated": "2026-08-21T19:31:45.169Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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