CVE-2021-41641: Deno Link Following Vulnerability

HIGH
Advisory Identifier: GHSA-67hm-27mx-9cg7
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CVSS 8.4
CWE-59
Published
Advisory Summary

CVE-2021-41641 is a HIGH (CVSS 8.4) link following vulnerability (CWE-59: Improper Link Resolution Before File Access ('Link Following')) affecting Deno libraries in the crates.io ecosystem. The issue involves link following in deno. Remediation is available by upgrading affected packages to version 1.16.0.

CVE-2021-41641 at a Glance

CVE Identifier CVE-2021-41641
GHSA Identifier GHSA-67hm-27mx-9cg7
Severity HIGH
CVSS v3.1 Base Score 8.4
CWE Classification CWE-59: Improper Link Resolution Before File Access ('Link Following')
Affected Product Deno
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 8.4

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2021-41641

To remediate this vulnerability, upgrade all affected Deno dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

deno fixed: 1.16.0 
Upgrade deno to 1.16.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for deno

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-41641, inspect your project dependencies for Deno:

inspect dependencies for deno

Analyze the terminal output to locate any version of Deno in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.16.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-59: Improper Link Resolution Before File Access ('Link Following'), where the product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource. In Deno, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Deno <=1.14.0 file sandbox does not handle symbolic links correctly. When running Deno with specific write access, the Deno.symlink method can be used to gain access to any directory.

CVE-2021-41641 Affected Deno Versions

1 component(s)
Fixed Versions:
1.16.0
Product / Package Ecosystem Affected Versions Fixed Version
deno
 crates.io
< 1.16.0
1.16.0

References

NVD — CVE-2021-41641 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-41641
Deno Source Repository REPOSITORY
https://github.com/denoland/deno/issues/12152
Deno Source Repository REPOSITORY
https://github.com/denoland/deno/pull/12554
Security Fix Commit FIX COMMIT
https://github.com/denoland/deno/commit/d44011a69e0674acfa9c59bd7ad7f0523eb61d42
hackers.report/report/614876917a7b... WEB
https://hackers.report/report/614876917a7b150012836bb8

Frequently Asked Questions

What is CVE-2021-41641?
CVE-2021-41641 is a security vulnerability in Deno involving Link Following in Deno under CWE-59: Improper Link Resolution Before File Access ('Link Following').
Which Deno versions are affected?
Affected versions include releases prior to 1.16.0 across affected packages: deno.
What version fixes CVE-2021-41641?
Upgrading to 1.16.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is deno affected?
Yes, deno is affected in releases prior to 1.16.0. Upgrade your dependency to 1.16.0 or later.
What is the CVSS score of CVE-2021-41641?
CVE-2021-41641 has a CVSS v3.1 base score of 8.4 (HIGH) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N.
What CWE is associated with CVE-2021-41641?
CVE-2021-41641 is classified under CWE-59: Improper Link Resolution Before File Access ('Link Following') (The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.).
How can I check crates.io dependencies for CVE-2021-41641?
Run the dependency tree command: 'inspect dependencies for deno'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-67hm-27mx-9cg7",
  "modified" : "2022-06-23T06:44:34Z",
  "published" : "2022-06-13T00:00:19Z",
  "aliases" : [ "CVE-2021-41641" ],
  "summary" : "Link Following in Deno",
  "details" : "Deno <=1.14.0 file sandbox does not handle symbolic links correctly. When running Deno with specific write access, the Deno.symlink method can be used to gain access to any directory.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "deno"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.16.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-41641"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/denoland/deno/issues/12152"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/denoland/deno/pull/12554"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/denoland/deno/commit/d44011a69e0674acfa9c59bd7ad7f0523eb61d42"
  }, {
    "type" : "WEB",
    "url" : "https://hackers.report/report/614876917a7b150012836bb8"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-59" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-06-23T06:44:34Z",
    "nvd_published_at" : "2022-06-12T13:15:00Z"
  }
}