CVE-2021-26600: Impresscms/impresscms Type Confusion Vulnerability

CRITICAL
Advisory Identifier: GHSA-m8xh-cqc2-5q6f
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CVSS 9.8
CWE-843
Published
Advisory Summary

CVE-2021-26600 is a CRITICAL (CVSS 9.8) type confusion vulnerability (CWE-843: Access of Resource Using Incompatible Type ('Type Confusion')) affecting Impresscms/impresscms libraries in the Packagist ecosystem. The issue involves type confusion in impresscms. Remediation is available by upgrading affected packages to version 1.4.3.

CVE-2021-26600 at a Glance

CVE Identifier CVE-2021-26600
GHSA Identifier GHSA-m8xh-cqc2-5q6f
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-843: Access of Resource Using Incompatible Type ('Type Confusion')
Affected Product Impresscms/impresscms
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 9.8

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:H/A:H).

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 High (I:H)
Availability High (A:H)

How to Fix CVE-2021-26600

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

impresscms/impresscms fixed: 1.4.3 
Upgrade impresscms/impresscms to 1.4.3
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 impresscms/impresscms

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-26600, inspect your project dependencies for Impresscms/impresscms:

inspect dependencies for impresscms/impresscms

Analyze the terminal output to locate any version of Impresscms/impresscms in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.4.3), 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-843: Access of Resource Using Incompatible Type ('Type Confusion'), where the product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type. In Impresscms/impresscms, 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

ImpressCMS before 1.4.3 has plugins/preloads/autologin.php type confusion with resultant Authentication Bypass (!= instead of !==).

CVE-2021-26600 Affected Impresscms/impresscms Versions

1 component(s)
Fixed Versions:
1.4.3
Product / Package Ecosystem Affected Versions Fixed Version
impresscms/impresscms
 Packagist
< 1.4.3
1.4.3

References

NVD — CVE-2021-26600 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-26600
hackerone.com/reports/1081986 WEB
https://hackerone.com/reports/1081986
Impresscms/impresscms Source Repository REPOSITORY
https://github.com/ImpressCMS/impresscms
Impresscms/impresscms Release RELEASE
https://github.com/ImpressCMS/impresscms/releases/tag/v1.4.3
Impresscms/impresscms Security Information SECURITY
http://karmainsecurity.com/KIS-2022-01
Impresscms/impresscms Security Information SECURITY
http://packetstormsecurity.com/files/166393/ImpressCMS-1.4.2-Authentication-Bypass.html
seclists.org/fulldisclosure/2022... WEB
http://seclists.org/fulldisclosure/2022/Mar/43

Frequently Asked Questions

What is CVE-2021-26600?
CVE-2021-26600 is a security vulnerability in Impresscms/impresscms involving Type Confusion in ImpressCMS under CWE-843: Access of Resource Using Incompatible Type ('Type Confusion').
Which Impresscms/impresscms versions are affected?
Affected versions include releases prior to 1.4.3 across affected packages: impresscms/impresscms.
What version fixes CVE-2021-26600?
Upgrading to 1.4.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is impresscms/impresscms affected?
Yes, impresscms/impresscms is affected in releases prior to 1.4.3. Upgrade your dependency to 1.4.3 or later.
What is the CVSS score of CVE-2021-26600?
CVE-2021-26600 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2021-26600?
CVE-2021-26600 is classified under CWE-843: Access of Resource Using Incompatible Type ('Type Confusion') (The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.).
How can I check Packagist dependencies for CVE-2021-26600?
Run the dependency tree command: 'inspect dependencies for impresscms/impresscms'. 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-m8xh-cqc2-5q6f",
  "modified" : "2022-04-01T17:14:56Z",
  "published" : "2022-03-29T00:01:16Z",
  "aliases" : [ "CVE-2021-26600" ],
  "summary" : "Type Confusion in ImpressCMS",
  "details" : "ImpressCMS before 1.4.3 has plugins/preloads/autologin.php type confusion with resultant Authentication Bypass (!= instead of !==).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "impresscms/impresscms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.4.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-26600"
  }, {
    "type" : "WEB",
    "url" : "https://hackerone.com/reports/1081986"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/ImpressCMS/impresscms"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ImpressCMS/impresscms/releases/tag/v1.4.3"
  }, {
    "type" : "WEB",
    "url" : "http://karmainsecurity.com/KIS-2022-01"
  }, {
    "type" : "WEB",
    "url" : "http://packetstormsecurity.com/files/166393/ImpressCMS-1.4.2-Authentication-Bypass.html"
  }, {
    "type" : "WEB",
    "url" : "http://seclists.org/fulldisclosure/2022/Mar/43"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-843" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-04-01T17:14:56Z",
    "nvd_published_at" : "2022-03-28T01:15:00Z"
  }
}