Vulnerability-Lookup

GHSA-JFWF-28XR-XW6Q

Vulnerability from github – Published: 2026-04-22 14:45 – Updated: 2026-04-22 14:45

Summary

RClone: Unauthenticated operations/fsinfo allows attacker-controlled backend instantiation and local command execution

Details

Summary

The RC endpoint operations/fsinfo is exposed without AuthRequired: true and accepts attacker-controlled fs input. Because rc.GetFs(...) supports inline backend definitions, an unauthenticated attacker can instantiate an attacker-controlled backend on demand. For the WebDAV backend, bearer_token_command is executed during backend initialization, making single-request unauthenticated local command execution possible on reachable RC deployments without global HTTP authentication.

Preconditions

Preconditions for this vulnerability are:

The rclone remote control API must be enabled, either by the --rc flag or by running the rclone rcd server
The remote control API must be reachable by the attacker - by default rclone only serves the rc to localhost unless the --rc-addr flag is in use
The rc must have been deployed without global RC HTTP authentication - so not using --rc-user/--rc-pass/--rc-htpasswd/etc

Details

The root cause consists of the following pieces:

operations/fsinfo is not protected with AuthRequired: true
operations/fsinfo calls rc.GetFs(...) on attacker-controlled input
rc.GetFs(...) supports inline backend creation through object-valued fs
WebDAV backend initialization executes bearer_token_command

Relevant code paths:

fs/operations/rc.go
operations/fsinfo is registered without AuthRequired: true
rcFsInfo() calls rc.GetFs(ctx, in)
fs/rc/cache.go
GetFs() / GetFsNamed() can parse an object-valued fs
getConfigMap() converts attacker-controlled JSON into a backend config string
backend/webdav/webdav.go
bearer_token_command is a supported backend option
NewFs(...) calls fetchAndSetBearerToken() when bearer_token_command is set
fetchBearerToken() invokes exec.Command(...)

This creates a practical single-request unauthenticated command-execution primitive on reachable RC servers without global HTTP authentication.

This was alidated on: - current master as of 2026-04-14: bf55d5e6d37fd86164a87782191f9e1ffcaafa82 - latest public release tested locally: v1.73.4

This was also validated on a public amd64 Ubuntu host controlled by the tester, using direct host execution (not containerized PoC execution).

PoC

Minimal single-request form PoC

Start a vulnerable RC server:

rclone rcd --rc-addr 127.0.0.1:5572

No --rc-user, no --rc-pass, no --rc-htpasswd.

Then send a single request:

curl -sS -X POST http://127.0.0.1:5572/operations/fsinfo \
  --data-urlencode "fs=:webdav,url='http://127.0.0.1/',vendor=other,bearer_token_command='/usr/bin/touch /tmp/rclone_fsinfo_rce_poc_marker':"

Expected result: - HTTP 200 JSON response from operations/fsinfo - /tmp/rclone_fsinfo_rce_poc_marker is created on the host

Impact

This is effectively a single-request unauthenticated command-execution vulnerability on reachable RC deployments without global HTTP authentication.

In practice, command execution in the rclone process context can lead to higher-impact outcomes such as local file read, file write, or shell access, depending on the deployed environment.

Testing performed

This was successfully reproduced: - on a local test environment - on a public amd64 Ubuntu host controlled by the tester

On the public host it was confirmed:

the unauthenticated operations/fsinfo exploit worked
command execution occurred on the host
the issue was reproducible through direct host execution

Severity ?

9.2 (Critical)


                  
                    CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.73.4"
      },
      "package": {
        "ecosystem": "Go",
        "name": "github.com/rclone/rclone"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.48.0"
            },
            {
              "fixed": "1.73.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-41179"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-306",
      "CWE-78"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-22T14:45:10Z",
    "nvd_published_at": null,
    "severity": "CRITICAL"
  },
  "details": "### Summary\nThe RC endpoint `operations/fsinfo` is exposed without `AuthRequired: true` and accepts attacker-controlled `fs` input. Because `rc.GetFs(...)` supports inline backend definitions, an unauthenticated attacker can instantiate an attacker-controlled backend on demand. For the WebDAV backend, `bearer_token_command` is executed during backend initialization, making single-request unauthenticated local command execution possible on reachable RC deployments without global HTTP authentication.\n\n### Preconditions\n\nPreconditions for this vulnerability are:\n\n- The rclone remote control API **must** be enabled, either by the `--rc` flag or by running the `rclone rcd` server\n- The remote control API **must** be reachable by the attacker - by default rclone only serves the rc to localhost unless the `--rc-addr` flag is in use\n- The rc must have been deployed **without** global RC HTTP authentication - so not using `--rc-user`/`--rc-pass`/`--rc-htpasswd`/etc\n\n\n### Details\nThe root cause consists of the following pieces:\n\n1. `operations/fsinfo` is not protected with `AuthRequired: true`\n2. `operations/fsinfo` calls `rc.GetFs(...)` on attacker-controlled input\n3. `rc.GetFs(...)` supports inline backend creation through object-valued `fs`\n4. WebDAV backend initialization executes `bearer_token_command`\n\nRelevant code paths:\n\n- [`fs/operations/rc.go`](https://github.com/rclone/rclone/blob/bf55d5e6d37fd86164a87782191f9e1ffcaafa82/fs/operations/rc.go)\n  - `operations/fsinfo` is registered without `AuthRequired: true`\n  - `rcFsInfo()` calls `rc.GetFs(ctx, in)`\n\n- [`fs/rc/cache.go`](https://github.com/rclone/rclone/blob/bf55d5e6d37fd86164a87782191f9e1ffcaafa82/fs/rc/cache.go)\n  - `GetFs()` / `GetFsNamed()` can parse an object-valued `fs`\n  - `getConfigMap()` converts attacker-controlled JSON into a backend config string\n\n- [`backend/webdav/webdav.go`](https://github.com/rclone/rclone/blob/bf55d5e6d37fd86164a87782191f9e1ffcaafa82/backend/webdav/webdav.go)\n  - `bearer_token_command` is a supported backend option\n  - `NewFs(...)` calls `fetchAndSetBearerToken()` when `bearer_token_command` is set\n  - `fetchBearerToken()` invokes `exec.Command(...)`\n\nThis creates a practical single-request unauthenticated command-execution primitive on reachable RC servers without global HTTP authentication.\n\nThis was alidated on:\n- current `master` as of 2026-04-14: `bf55d5e6d37fd86164a87782191f9e1ffcaafa82`\n- latest public release tested locally: `v1.73.4`\n\nThis was also validated on a public amd64 Ubuntu host controlled by the tester, using direct host execution (not containerized PoC execution).\n\n### PoC\n#### Minimal single-request form PoC\nStart a vulnerable RC server:\n\n```bash\nrclone rcd --rc-addr 127.0.0.1:5572\n```\n\nNo `--rc-user`, no `--rc-pass`, no `--rc-htpasswd`.\n\nThen send a single request:\n\n```bash\ncurl -sS -X POST http://127.0.0.1:5572/operations/fsinfo \\\n  --data-urlencode \"fs=:webdav,url=\u0027http://127.0.0.1/\u0027,vendor=other,bearer_token_command=\u0027/usr/bin/touch /tmp/rclone_fsinfo_rce_poc_marker\u0027:\"\n```\n\nExpected result:\n- HTTP 200 JSON response from `operations/fsinfo`\n- `/tmp/rclone_fsinfo_rce_poc_marker` is created on the host\n\n### Impact\nThis is effectively a single-request unauthenticated command-execution vulnerability on reachable RC deployments without global HTTP authentication.\n\nIn practice, command execution in the rclone process context can lead to higher-impact outcomes such as local file read, file write, or shell access, depending on the deployed environment.\n\n#### Testing performed\nThis was successfully reproduced:\n- on a local test environment\n- on a public amd64 Ubuntu host controlled by the tester\n\nOn the public host it was confirmed:\n\n- the unauthenticated `operations/fsinfo` exploit worked\n- command execution occurred on the host\n- the issue was reproducible through direct host execution",
  "id": "GHSA-jfwf-28xr-xw6q",
  "modified": "2026-04-22T14:45:10Z",
  "published": "2026-04-22T14:45:10Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/rclone/rclone/security/advisories/GHSA-jfwf-28xr-xw6q"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/rclone/rclone"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "RClone: Unauthenticated operations/fsinfo allows attacker-controlled backend instantiation and local command execution"
}

CVE-2026-41179 (GCVE-0-2026-41179)

Vulnerability from cvelistv5 – Published: 2026-04-23 00:03 – Updated: 2026-04-25 03:55

Title

RClone: Unauthenticated operations/fsinfo allows attacker-controlled backend instantiation and local command execution

Summary

Rclone is a command-line program to sync files and directories to and from different cloud storage providers. Starting in version 1.48.0 and prior to version 1.73.5, the RC endpoint `operations/fsinfo` is exposed without `AuthRequired: true` and accepts attacker-controlled `fs` input. Because `rc.GetFs(...)` supports inline backend definitions, an unauthenticated attacker can instantiate an attacker-controlled backend on demand. For the WebDAV backend, `bearer_token_command` is executed during backend initialization, making single-request unauthenticated local command execution possible on reachable RC deployments without global HTTP authentication. Version 1.73.5 patches the issue.

Severity ?

9.2 (Critical)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CWE

CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CWE-306 - Missing Authentication for Critical Function

Assigner

GitHub_M

References

URL

Tags

	https://github.com/rclone/rclone/security/advisor…	x_refsource_CONFIRM
	https://github.com/rclone/rclone/blob/bf55d5e6d37…	x_refsource_MISC
	https://github.com/rclone/rclone/blob/bf55d5e6d37…	x_refsource_MISC
	https://github.com/rclone/rclone/blob/bf55d5e6d37…	x_refsource_MISC

Impacted products

	Vendor	Product	Version
	rclone	rclone	Affected: >= 1.48.0, < 1.73.5

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-41179",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-24T00:00:00+00:00",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-25T03:55:41.241Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "rclone",
          "vendor": "rclone",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 1.48.0, \u003c 1.73.5"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Rclone is a command-line program to sync files and directories to and from different cloud storage providers. Starting in version 1.48.0 and prior to version 1.73.5, the RC endpoint `operations/fsinfo` is exposed without `AuthRequired: true` and accepts attacker-controlled `fs` input. Because `rc.GetFs(...)` supports inline backend definitions, an unauthenticated attacker can instantiate an attacker-controlled backend on demand. For the WebDAV backend, `bearer_token_command` is executed during backend initialization, making single-request unauthenticated local command execution possible on reachable RC deployments without global HTTP authentication. Version 1.73.5 patches the issue."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 9.2,
            "baseSeverity": "CRITICAL",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH"
          }
        }
      ],
      "problemTypes": [
        {
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              "description": "CWE-78: Improper Neutralization of Special Elements used in an OS Command (\u0027OS Command Injection\u0027)",
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              "type": "CWE"
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        {
          "descriptions": [
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              "description": "CWE-306: Missing Authentication for Critical Function",
              "lang": "en",
              "type": "CWE"
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          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-23T00:03:36.282Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/rclone/rclone/security/advisories/GHSA-jfwf-28xr-xw6q",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/rclone/rclone/security/advisories/GHSA-jfwf-28xr-xw6q"
        },
        {
          "name": "https://github.com/rclone/rclone/blob/bf55d5e6d37fd86164a87782191f9e1ffcaafa82/backend/webdav/webdav.go",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/rclone/rclone/blob/bf55d5e6d37fd86164a87782191f9e1ffcaafa82/backend/webdav/webdav.go"
        },
        {
          "name": "https://github.com/rclone/rclone/blob/bf55d5e6d37fd86164a87782191f9e1ffcaafa82/fs/operations/rc.go",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/rclone/rclone/blob/bf55d5e6d37fd86164a87782191f9e1ffcaafa82/fs/operations/rc.go"
        },
        {
          "name": "https://github.com/rclone/rclone/blob/bf55d5e6d37fd86164a87782191f9e1ffcaafa82/fs/rc/cache.go",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/rclone/rclone/blob/bf55d5e6d37fd86164a87782191f9e1ffcaafa82/fs/rc/cache.go"
        }
      ],
      "source": {
        "advisory": "GHSA-jfwf-28xr-xw6q",
        "discovery": "UNKNOWN"
      },
      "title": "RClone: Unauthenticated operations/fsinfo allows attacker-controlled backend instantiation and local command execution"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-41179",
    "datePublished": "2026-04-23T00:03:36.282Z",
    "dateReserved": "2026-04-17T16:34:45.526Z",
    "dateUpdated": "2026-04-25T03:55:41.241Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

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.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-JFWF-28XR-XW6Q

Summary

Preconditions

Details

PoC

Minimal single-request form PoC

Impact

Testing performed

CVE-2026-41179 (GCVE-0-2026-41179)

Tags

Sightings

Nomenclature