CVE-2021-41617 is a high-severity vulnerability found in OpenSSH versions 6.2 through 8.x prior to 8.8. This vulnerability allows privilege escalation due to the improper initialization of supplemental groups when certain non-default configurations are used. The potential for exploitation arises when helper programs for AuthorizedKeysCommand and AuthorizedPrincipalsCommand are executed with privileges associated with group memberships of the sshd process.
The CVSS score for this vulnerability is 7, indicating a high level of risk. It is essential for organizations using affected versions of OpenSSH to prioritize patching, as the consequences of exploitation can lead to unauthorized access and control over systems, impacting confidentiality, integrity, and availability.
Risk to organizations includes significant exposure to local attacks that could lead to privilege escalation, especially in configurations where commands are executed with different user privileges. Organizations should address this vulnerability immediately to mitigate risks.
Currently, there is evidence of public proof of concept (PoC) code available on GitHub, which indicates that this vulnerability could be exploited in the wild. Organizations are urged to take immediate action to remediate this issue.
Given the potential impact and the availability of exploit code, this vulnerability should be treated with high urgency.
Vulnerability Details
The official description of CVE-2021-41617 states that sshd in OpenSSH 6.2 through 8.x before 8.8, when certain non-default configurations are used, allows privilege escalation because supplemental groups are not initialized as expected. This issue can be exploited if the configuration specifies running the command as a different user.
The vulnerability has a CVSS v3.1 score of 7.0, which indicates high severity. The attack vector is local, and the attack complexity is rated as high, requiring low privileges and no user interaction. The impacts on confidentiality, integrity, and availability are all high.
Technical Analysis
The root cause of the vulnerability is the failure to properly initialize supplemental groups, allowing unauthorized execution of commands with elevated privileges. The attack vector is local, meaning that an attacker must have access to the local system to exploit this vulnerability. The attack complexity is high due to the need for specific configuration settings.
Privileges required for exploitation are low, meaning an attacker does not need extensive permissions to exploit this vulnerability. Additionally, no user interaction is required, making it easier for an attacker to leverage this vulnerability.
The impacts of this vulnerability are severe, with high potential for unauthorized access and control over affected systems, which could lead to data breaches and service disruptions.
Risk & Impact Analysis
The risk to organizations includes exposure to local attacks that could result in unauthorized access and privilege escalation. The blast radius may be significant, especially in environments that rely on OpenSSH for secure communications and remote access.
Organizations should assess their configurations and patch affected systems immediately. The urgency for remediation is high due to the nature of the vulnerability and the potential for it to be exploited in the wild.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | Yes |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
Affected versions include OpenSSH 6.2 through 8.x prior to 8.8, as well as various versions of Fedora (33, 34, 35) and NetApp products such as Active IQ Unified Manager and clustered Data ONTAP.
Mitigation & Remediation
Organizations should prioritize patching affected systems to version 8.8 or later to remediate this vulnerability. If patches are not immediately available, configuration changes should be implemented to mitigate risk. This may include limiting the use of non-default configurations for AuthorizedKeysCommand and AuthorizedPrincipalsCommand.
For additional guidance, organizations can consult the penetration testing services to assess their security posture.
Detection Guidance
Organizations should monitor logs for unusual SSH activity, specifically regarding the execution of commands associated with AuthorizedKeysCommand and AuthorizedPrincipalsCommand. Behavioral anomalies and changes in user privileges should also be closely watched.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-41617 lies in its representation of the challenges associated with SSH configurations and privilege management. Security teams should take note of the importance of default configurations and the risks of deviating from best practices.
This vulnerability serves as a reminder of the necessity for continuous security assessments and the value of penetration testing methodologies to identify potential weaknesses.
Moreover, organizations should leverage vulnerability management programs to proactively address such vulnerabilities before they can be exploited.
In conclusion, CVE-2021-41617 highlights critical areas for improvement in privilege management and configuration practices within SSH implementations.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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