A vulnerability has been reported in the windows installer (MSI) built with InstallScript custom action. This vulnerability may allow privilege escalation when invoked ‘repair’ of the MSI which has an InstallScript custom action. The Common Vulnerability Scoring System (CVSS) version 3.1 has assigned a score of 7.8, indicating a high-severity risk to organizations using affected versions of the software. The attack vector is local, suggesting that an attacker would need access to the system to exploit this vulnerability. Given the potential for privilege escalation, organizations should prioritize patching immediately.
Organizations should be aware that risk to organizations includes unauthorized access to sensitive data and system control, which can result in further exploitations or data breaches. The lack of public exploits or known attacks does not diminish the urgency of addressing this vulnerability, as attackers may develop methods to exploit it in the future.
Effective remediation is necessary to mitigate this vulnerability. Organizations should keep their systems updated and apply patches as soon as they are available from the vendor. Additionally, regular security assessments and monitoring can help identify any attempts to exploit vulnerabilities like CVE-2021-41526.
In response to this vulnerability, Flexera has made updates available. Organizations must ensure that their systems are running the latest versions of Flexera Revenera InstallShield to mitigate the associated risks.
Vulnerability Details
The vulnerability allows for privilege escalation due to improper handling of the InstallScript custom actions during the MSI repair process. The vulnerability has been classified with a CVSS score of 7.8, categorized as high severity, which indicates a significant risk to systems. The affected product is Flexera Revenera InstallShield with versions, including those prior to 2021 and the 2021 releases.
Technical Analysis
The root cause of this vulnerability stems from the interaction between the InstallScript custom actions and the MSI repair functionality. When an MSI containing InstallScript custom actions is repaired, it potentially allows an attacker with local access to escalate privileges beyond their intended access level.
The attack vector is local, requiring an attacker to have access to the system. The complexity of the attack is low, as it does not require significant technical skill or user interaction. Privileges required are considered low, allowing even standard users to potentially exploit this vulnerability if they have access to the MSI in question.
The impact of this vulnerability is significant, with high confidentiality, integrity, and availability impacts. Organizations should recognize that any successful exploitation could lead to unauthorized access and manipulation of sensitive data, which can severely affect business operations.
Risk & Impact Analysis
Organizations that utilize Flexera Revenera InstallShield should assess the real-world deployment risk of this vulnerability. Given the high severity score, the blast radius potential is significant, as this vulnerability could impact multiple systems within an organization if exploited.
The urgency for patching this vulnerability is critical; organizations should prioritize this in their patch management cycles. The lack of known exploitation does not reduce the risk; rather, it emphasizes the need for proactive measures to prevent any potential future exploits.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions of Flexera Revenera InstallShield include all versions prior to 2021, as well as the 2021 releases. Organizations should ensure their systems are updated to the latest versions to mitigate this vulnerability.
Mitigation & Remediation
To mitigate this vulnerability, organizations should immediately apply the latest patches from Flexera for the Revenera InstallShield. If patches are not available, implementing security controls such as restricting access to the MSI files and monitoring for unusual activity on systems can help reduce the risk.
Organizations may also benefit from conducting regular security assessments and penetration testing to identify vulnerabilities and ensure robust defenses against potential exploits. For a comprehensive approach, consider engaging in penetration testing to verify the effectiveness of implemented security measures.
Detection Guidance
Organizations should monitor log files for unusual access patterns or errors related to MSI repairs. Behavioral anomalies such as unauthorized attempts to invoke the repair functionality should be flagged for investigation. Network signatures for known exploits should be updated, and any changes to system configurations must be reviewed regularly to detect potential exploitation attempts.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-41526 highlights the necessity for organizations to maintain vigilant security practices around software installations and updates. This vulnerability represents a pattern of privilege escalation risks associated with installation processes that rely on custom scripts.
Security teams are reminded of the importance of holistic security assessments that encompass all software components, especially those related to installation frameworks. For insights on security testing best practices, refer to security testing best practices and penetration testing methodology to enhance overall security posture.
Finally, organizations are encouraged to stay informed about emerging threats and vulnerabilities, adapting their security measures accordingly. Engaging with resources such as vulnerability management programs can provide valuable insights in navigating a landscape of evolving threats.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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