CVE-2021-32791 Vulnerability Analysis & Exploit Details

CVE-2021-32791
Vulnerability Scoring

5.9
/10
Significant Risk

Security assessments indicate that CVE-2021-32791 presents a notable risk, potentially requiring prompt mitigation.

Attack Complexity Details

  • Attack Complexity: High
    Exploits require significant effort and special conditions.
  • Attack Vector: Network
    Vulnerability is exploitable over a network without physical access.
  • Privileges Required: None
    No privileges are required for exploitation.
  • Scope: Unchanged
    Exploit remains within the originally vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2021-32791 Details

Status: Modified

Last updated: 🕕 21 Nov 2024, 06:07 UTC
Originally published on: 🕔 26 Jul 2021, 17:15 UTC

Time between publication and last update: 1213 days

CVSS Release: version 3

CVSS3 Source

security-advisories@github.com

CVSS3 Type

Secondary

CVSS3 Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

CVE-2021-32791 Vulnerability Summary

CVE-2021-32791: mod_auth_openidc is an authentication/authorization module for the Apache 2.x HTTP server that functions as an OpenID Connect Relying Party, authenticating users against an OpenID Connect Provider. In mod_auth_openidc before version 2.4.9, the AES GCM encryption in mod_auth_openidc uses a static IV and AAD. It is important to fix because this creates a static nonce and since aes-gcm is a stream cipher, this can lead to known cryptographic issues, since the same key is being reused. From 2.4.9 onwards this has been patched to use dynamic values through usage of cjose AES encryption routines.

Assessing the Risk of CVE-2021-32791

Access Complexity Graph

The exploitability of CVE-2021-32791 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).

Exploitability Analysis for CVE-2021-32791

CVE-2021-32791 presents a challenge to exploit due to its high attack complexity, but the absence of privilege requirements still makes it a viable target for skilled attackers. A thorough security review is advised.

Understanding AC and PR

A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.

Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.

Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.

CVSS Score Breakdown Chart

Above is the CVSS Sub-score Breakdown for CVE-2021-32791, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.

CIA Impact Analysis

Below is the Impact Analysis for CVE-2021-32791, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: High
    Exploiting CVE-2021-32791 can result in unauthorized access to sensitive data, severely compromising data privacy.
  • Integrity: None
    CVE-2021-32791 poses no threat to data integrity.
  • Availability: None
    CVE-2021-32791 does not impact system availability.

Exploit Prediction Scoring System (EPSS)

The EPSS score estimates the probability that this vulnerability will be exploited in the near future.

EPSS Score: 0.212% (probability of exploit)

EPSS Percentile: 59.67% (lower percentile = lower relative risk)
This vulnerability is less risky than approximately 40.33% of others.

CVE-2021-32791 References

External References

CWE Common Weakness Enumeration

CWE-330

CAPEC Common Attack Pattern Enumeration and Classification

  • Brute Force CAPEC-112 In this attack, some asset (information, functionality, identity, etc.) is protected by a finite secret value. The attacker attempts to gain access to this asset by using trial-and-error to exhaustively explore all the possible secret values in the hope of finding the secret (or a value that is functionally equivalent) that will unlock the asset.
  • Signature Spoofing by Key Recreation CAPEC-485 An attacker obtains an authoritative or reputable signer's private signature key by exploiting a cryptographic weakness in the signature algorithm or pseudorandom number generation and then uses this key to forge signatures from the original signer to mislead a victim into performing actions that benefit the attacker.
  • Session Credential Falsification through Prediction CAPEC-59 This attack targets predictable session ID in order to gain privileges. The attacker can predict the session ID used during a transaction to perform spoofing and session hijacking.

Vulnerable Configurations

  • cpe:2.3:a:openidc:mod_auth_openidc:-:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:-:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.5:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.5:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.5.1:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.5.1:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.5.2:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.5.2:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.5.3:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.5.3:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.5.4:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.5.4:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.5.5:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.5.5:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.6.0:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.6.0:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.7.0:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.7.0:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.7.1:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.7.1:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.7.2:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.7.2:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.7.3:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.7.3:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.8.0:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.8.0:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.8.1:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.8.1:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.8.2:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.8.2:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.8.3:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.8.3:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.8.4:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.8.4:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.8.5:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.8.5:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.8.6:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.8.6:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.8.7:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.8.7:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.8.8:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.8.8:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.8.9:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.8.9:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.8.10:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.8.10:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.8.10.1:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.8.10.1:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.8.10.2:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.8.10.2:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:1.8.10.3:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:1.8.10.3:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.0.0:-:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.0.0:-:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.0.0:rc1:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.0.0:rc1:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.0.0:rc4:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.0.0:rc4:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.1.0:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.1.0:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.1.1:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.1.1:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.1.2:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.1.2:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.1.3:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.1.3:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.1.4:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.1.4:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.1.5:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.1.5:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.1.6:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.1.6:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.1.13:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.1.13:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.2.0:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.2.0:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.3.0:-:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.3.0:-:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.3.0:rc0:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.3.0:rc0:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.3.0:rc3:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.3.0:rc3:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.3.1:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.3.1:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.3.2:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.3.2:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.3.3:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.3.3:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.3.4:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.3.4:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.3.5:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.3.5:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.3.6:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.3.6:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.3.7:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.3.7:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.3.8:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.3.8:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.3.9:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.3.9:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.3.10:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.3.10:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.3.10.1:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.3.10.1:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.3.10.2:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.3.10.2:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.3.11:-:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.3.11:-:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.3.11:rc1:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.3.11:rc1:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.0:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.0:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.0.1:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.0.1:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.0.2:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.0.2:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.0.3:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.0.3:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.0.4:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.0.4:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.1:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.1:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.2:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.2:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.2.1:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.2.1:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.3:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.3:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.4:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.4:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.4.1:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.4.1:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.5:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.5:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.6:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.6:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.7:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.7:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.7.1:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.7.1:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.7.2:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.7.2:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.8.1:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.8.1:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.8.2:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.8.2:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.8.3:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.8.3:*:*:*:*:*:*:*
  • cpe:2.3:a:openidc:mod_auth_openidc:2.4.8.4:*:*:*:*:*:*:*
    cpe:2.3:a:openidc:mod_auth_openidc:2.4.8.4:*:*:*:*:*:*:*
  • cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*
    cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*
  • cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
    cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
  • cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
    cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

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