CVE-2021-29437 Vulnerability Analysis & Exploit Details

CVE-2021-29437
Vulnerability Scoring

8.0
/10
Very High Risk

Highly exploitable, CVE-2021-29437 poses a critical security risk that could lead to severe breaches.

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: Changed
    Successful exploitation can impact components beyond the vulnerable component.
  • User Interaction: Required
    User interaction is necessary for successful exploitation.

CVE-2021-29437 Details

Status: Modified

Last updated: 🕕 21 Nov 2024, 06:01 UTC
Originally published on: 🕗 13 Apr 2021, 20:15 UTC

Time between publication and last update: 1317 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:R/S:C/C:H/I:H/A:N

CVE-2021-29437 Vulnerability Summary

CVE-2021-29437: ScratchOAuth2 is an Oauth implementation for Scratch. Any ScratchOAuth2-related data normally accessible and modifiable by a user can be read and modified by a third party. 1. Scratch user visits 3rd party site. 2. 3rd party site asks user for Scratch username. 3. 3rd party site pretends to be user and gets login code from ScratchOAuth2. 4. 3rd party site gives code to user and instructs them to post it on their profile. 5. User posts code on their profile, not knowing it is a ScratchOAuth2 login code. 6. 3rd party site completes login with ScratchOAuth2. 7. 3rd party site has full access to anything the user could do if they directly logged in. See referenced GitHub security advisory for patch notes and workarounds.

Assessing the Risk of CVE-2021-29437

Access Complexity Graph

The exploitability of CVE-2021-29437 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-2021-29437

CVE-2021-29437 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-2021-29437, 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-2021-29437, 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-2021-29437 can result in unauthorized access to sensitive data, severely compromising data privacy.
  • Integrity: High
    CVE-2021-29437 could allow unauthorized modifications to data, potentially affecting system reliability and trust.
  • Availability: None
    CVE-2021-29437 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: 0.124% (probability of exploit)

EPSS Percentile: 48.34% (lower percentile = lower relative risk)
This vulnerability is less risky than approximately 51.66% of others.

CVE-2021-29437 References

External References

CWE Common Weakness Enumeration

NVD-CWE-noinfo

Vulnerable Configurations

  • cpe:2.3:a:scratchoauth2_project:scratchoauth2:-:*:*:*:*:scratch:*:*
    cpe:2.3:a:scratchoauth2_project:scratchoauth2:-:*:*:*:*:scratch:*:*

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