CVE-2020-29529: Github.com/hashicorp/go slug Unsafe Tar Unpacking Vulnerability

HIGH
Advisory Identifier: GHSA-2g5j-5x95-r6hr
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CVSS 7.5
CWE-59 CWE-22
Published
Advisory Summary

CVE-2020-29529 is a HIGH (CVSS 7.5) unsafe tar unpacking vulnerability (CWE-59: Improper Link Resolution Before File Access ('Link Following')) affecting Github.com/hashicorp/go slug libraries in the Go ecosystem. The issue involves unsafe tar unpacking in hashicorp go-slug. Remediation is available by upgrading affected packages to version 0.5.0.

CVE-2020-29529 at a Glance

CVE Identifier CVE-2020-29529
GHSA Identifier GHSA-2g5j-5x95-r6hr
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-59: Improper Link Resolution Before File Access ('Link Following')
Affected Product Github.com/hashicorp/go slug
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 7.5

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

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

How to Fix CVE-2020-29529

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

github.com/hashicorp/go-slug fixed: 0.5.0 
Upgrade github.com/hashicorp/go-slug to 0.5.0
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 github.com/hashicorp/go-slug

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-29529, inspect your project dependencies for Github.com/hashicorp/go slug:

inspect dependencies for github.com/hashicorp/go-slug

Analyze the terminal output to locate any version of Github.com/hashicorp/go slug in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.5.0), 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 Github.com/hashicorp/go slug, 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

HashiCorp go-slug before 0.5.0 does not address attempts at directory traversal involving ../ and symlinks.

CVE-2020-29529 Affected Github.com/hashicorp/go slug Versions

1 component(s)
Fixed Versions:
0.5.0
Product / Package Ecosystem Affected Versions Fixed Version
github.com/hashicorp/go-slug
golang/github.com/hashicorp/go-slug
Go
< 0.5.0
0.5.0

References

NVD — CVE-2020-29529 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-29529
Github.com/hashicorp/go slug Source Repository REPOSITORY
https://github.com/hashicorp/go-slug/pull/12
Security Fix Commit FIX COMMIT
https://github.com/hashicorp/go-slug/commit/28cafc59c8da6126a3ae94dfa84181df4073454f
Security Fix Commit FIX COMMIT
https://github.com/hashicorp/go-slug/commit/764785bc4cbb9e600ad1cf1a6bd21b535c182983
Github.com/hashicorp/go slug Source Repository REPOSITORY
https://github.com/hashicorp/go-slug
Github.com/hashicorp/go slug Source Repository REPOSITORY
https://github.com/hashicorp/go-slug/compare/v0.4.3...v0.5.0
Github.com/hashicorp/go slug Release RELEASE
https://github.com/hashicorp/go-slug/releases/tag/v0.5.0
pkg.go.dev/vuln/go-2021-0094 WEB
https://pkg.go.dev/vuln/GO-2021-0094
GitHub Advisory / Wiki ADVISORY
https://securitylab.github.com/advisories/GHSL-2020-262-zipslip-go-slug

Frequently Asked Questions

What is CVE-2020-29529?
CVE-2020-29529 is a security vulnerability in Github.com/hashicorp/go slug involving Unsafe tar unpacking in HashiCorp go-slug under CWE-59: Improper Link Resolution Before File Access ('Link Following').
Which Github.com/hashicorp/go slug versions are affected?
Affected versions include releases prior to 0.5.0 across affected packages: github.com/hashicorp/go-slug.
What version fixes CVE-2020-29529?
Upgrading to 0.5.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/hashicorp/go-slug affected?
Yes, github.com/hashicorp/go-slug is affected in releases prior to 0.5.0. Upgrade your dependency to 0.5.0 or later.
What is the CVSS score of CVE-2020-29529?
CVE-2020-29529 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2020-29529?
CVE-2020-29529 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 Go dependencies for CVE-2020-29529?
Run the dependency tree command: 'inspect dependencies for github.com/hashicorp/go-slug'. 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-2g5j-5x95-r6hr",
  "modified" : "2023-02-06T23:16:16Z",
  "published" : "2023-02-06T23:16:16Z",
  "aliases" : [ "CVE-2020-29529" ],
  "summary" : "Unsafe tar unpacking in HashiCorp go-slug",
  "details" : "HashiCorp go-slug before 0.5.0 does not address attempts at directory traversal involving ../ and symlinks.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/hashicorp/go-slug"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.5.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-29529"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/hashicorp/go-slug/pull/12"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/hashicorp/go-slug/commit/28cafc59c8da6126a3ae94dfa84181df4073454f"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/hashicorp/go-slug/commit/764785bc4cbb9e600ad1cf1a6bd21b535c182983"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/hashicorp/go-slug"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/hashicorp/go-slug/compare/v0.4.3...v0.5.0"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/hashicorp/go-slug/releases/tag/v0.5.0"
  }, {
    "type" : "WEB",
    "url" : "https://pkg.go.dev/vuln/GO-2021-0094"
  }, {
    "type" : "ADVISORY",
    "url" : "https://securitylab.github.com/advisories/GHSL-2020-262-zipslip-go-slug"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22", "CWE-59" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-02-06T23:16:16Z",
    "nvd_published_at" : null
  }
}