GHSA-P3X5-MVMP-5F35

Vulnerability from github – Published: 2025-10-02 21:16 – Updated: 2025-11-05 22:03
VLAI
Summary
Canonical LXD Project Existence Determination Through Error Handling in Image Export Function
Details

Impact

In LXD's images export API (/1.0/images/{fingerprint}/export), implementation differences in error handling allow determining project existence without authentication.

Specifically, in the following code, errors when multiple images match are directly returned to users as API responses:

https://github.com/canonical/lxd/blob/43d5189564d27f6161b430ed258c8b56603c2759/lxd/db/images.go#L239-L246

While fingerprints generally don't duplicate, this functionality uses fingerprints with LIKE clauses, allowing prefix specification. Therefore, using LIKE wildcards such as % will match multiple images if multiple images exist in the project.

https://github.com/canonical/lxd/blob/43d5189564d27f6161b430ed258c8b56603c2759/lxd/db/images.go#L277-L286

In the above implementation, multiple matches result in a 500 error, but if the project itself doesn't exist, there are 0 matches and a 404 is returned.

  1. When project exists and multiple images match: HTTP 500 error "More than one image matches"
  2. When project doesn't exist: HTTP 404 error "not found"

This behavioural difference allows attackers to confirm project existence without authentication.

Reproduction Steps

  1. Send a request with a pattern matching multiple entries to an existing project (default):
curl -k 'https://lxd-host:8443/1.0/images/%25/export?project=default&secret=x'

Response:

{"type":"error","status":"","status_code":0,"operation":"","error_code":500,"error":"More than one image matches","metadata":null}
  1. Send a same request to a non-existent project (not-exist):
curl -k 'https://lxd-host:8443/1.0/images/%25/export?project=not-exist&secret=x'

Response:

{"type":"error","status":"","status_code":0,"operation":"","error_code":404,"error":"not found","metadata":null}

This difference allows enumerating existing projects in the system by brute-forcing(dictionary attack) project names.

Note that %25 is the URL encoding of %, which works as a wildcard matching all characters in SQL LIKE clauses. This is used to intentionally create requests matching multiple images to trigger a 500 error.

Additionally, the secret parameter is added to include non-public images in the search, increasing the possibility of multiple matches.

https://github.com/canonical/lxd/blob/43d5189564d27f6161b430ed258c8b56603c2759/lxd/images.go#L4211-L4230

Risk

The attack requires only network access to the LXD API endpoint, with no authentication needed.

The attack allows confirming the existence of projects within the LXD system by exploiting differences in HTTP status codes. This could potentially increase the exploitability of other vulnerabilities. Additionally, since project IDs often use meaningful names set by users, this could lead to leakage of unpublished product information.

However, resource information within projects cannot be obtained, limiting the impact to existence confirmation only.

Countermeasures

It is recommended to modify error handling in the images export API (/1.0/images/{fingerprint}/export) to return consistent responses regardless of project existence.

Specifically, return 404 even when errors occur during project existence verification. This ensures the same error response is returned for both existing and non-existing projects, preventing determination of project existence.

Additionally, if there are no specification(compatibility) issues, allowing only exact fingerprint matches in unauthenticated states and disabling prefix matching can prevent unexpected errors from occurring.

Patches

LXD Series Status
6 Fixed in LXD 6.5
5.21 Fixed in LXD 5.21.4
5.0 Ignored - Not critical
4.0 Ignored - EOL and not critical

References

Reported by GMO Flatt Security Inc.

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/canonical/lxd"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0"
            },
            {
              "fixed": "5.21.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/canonical/lxd"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.0"
            },
            {
              "fixed": "6.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/canonical/lxd"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.0.0-20200331193331-03aab09f5b5c"
            },
            {
              "fixed": "0.0.0-20250827065555-0494f5d47e41"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-54290"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-200"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-10-02T21:16:27Z",
    "nvd_published_at": "2025-10-02T10:15:39Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\nIn LXD\u0027s images export API (`/1.0/images/{fingerprint}/export`), implementation differences in error handling allow determining project existence without authentication.\n\nSpecifically, in the following code, errors when multiple images match are directly returned to users as API responses:\n\nhttps://github.com/canonical/lxd/blob/43d5189564d27f6161b430ed258c8b56603c2759/lxd/db/images.go#L239-L246\n\nWhile fingerprints generally don\u0027t duplicate, this functionality uses fingerprints with LIKE clauses, allowing prefix specification. Therefore, using LIKE wildcards such as % will match multiple images if multiple images exist in the project.\n\nhttps://github.com/canonical/lxd/blob/43d5189564d27f6161b430ed258c8b56603c2759/lxd/db/images.go#L277-L286\n\nIn the above implementation, multiple matches result in a 500 error, but if the project itself doesn\u0027t exist, there are 0 matches and a 404 is returned.\n\n1. When project exists and multiple images match: HTTP 500 error \"More than one image matches\"\n2. When project doesn\u0027t exist: HTTP 404 error \"not found\" \n \nThis behavioural difference allows attackers to confirm project existence without authentication.\n\n### Reproduction Steps\n1. Send a request with a pattern matching multiple entries to an existing project (default):\n\n```\ncurl -k \u0027https://lxd-host:8443/1.0/images/%25/export?project=default\u0026secret=x\u0027\n```\n\nResponse:\n\n```json\n{\"type\":\"error\",\"status\":\"\",\"status_code\":0,\"operation\":\"\",\"error_code\":500,\"error\":\"More than one image matches\",\"metadata\":null}\n```\n\n2. Send a same request to a non-existent project (not-exist):\n\n```\ncurl -k \u0027https://lxd-host:8443/1.0/images/%25/export?project=not-exist\u0026secret=x\u0027\n```\n\nResponse:\n\n```json\n{\"type\":\"error\",\"status\":\"\",\"status_code\":0,\"operation\":\"\",\"error_code\":404,\"error\":\"not found\",\"metadata\":null}\n```\n\nThis difference allows enumerating existing projects in the system by brute-forcing(dictionary attack) project names.\n\nNote that `%25` is the URL encoding of `%`, which works as a wildcard matching all characters in SQL LIKE clauses. \nThis is used to intentionally create requests matching multiple images to trigger a 500 error.\n\nAdditionally, the secret parameter is added to include non-public images in the search, increasing the possibility of multiple matches.\n\nhttps://github.com/canonical/lxd/blob/43d5189564d27f6161b430ed258c8b56603c2759/lxd/images.go#L4211-L4230\n\n### Risk\nThe attack requires only network access to the LXD API endpoint, with no authentication needed.\n\nThe attack allows confirming the existence of projects within the LXD system by exploiting differences in HTTP status codes. This could potentially increase the exploitability of other vulnerabilities. Additionally, since project IDs often use meaningful names set by users, this could lead to leakage of unpublished product information. \n\nHowever, resource information within projects cannot be obtained, limiting the impact to existence confirmation only.\n\n### Countermeasures\nIt is recommended to modify error handling in the images export API (`/1.0/images/{fingerprint}/export`) to return consistent responses regardless of project existence. \n\nSpecifically, return 404 even when errors occur during project existence verification.\nThis ensures the same error response is returned for both existing and non-existing projects, preventing determination of project existence.\n\nAdditionally, if there are no specification(compatibility) issues, allowing only exact fingerprint matches in unauthenticated states and disabling prefix matching can prevent unexpected errors from occurring.\n\n### Patches\n\n| LXD Series  | Status |\n| ------------- | ------------- |\n| 6 | Fixed in LXD 6.5  |\n| 5.21 | Fixed in LXD 5.21.4  |\n| 5.0 | Ignored - Not critical |\n| 4.0  | Ignored - EOL and not critical |\n\n### References\nReported by GMO Flatt Security Inc.",
  "id": "GHSA-p3x5-mvmp-5f35",
  "modified": "2025-11-05T22:03:48Z",
  "published": "2025-10-02T21:16:27Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/canonical/lxd/security/advisories/GHSA-p3x5-mvmp-5f35"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-54290"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/canonical/lxd"
    },
    {
      "type": "WEB",
      "url": "https://pkg.go.dev/vuln/GO-2025-4002"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Canonical LXD Project Existence Determination Through Error Handling in Image Export Function"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON
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.

Events included in the timeline

Loading timeline…


    Loading…

    Loading…

    Loading…

    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.