CVE-2020-1986 in Secdo
Summary
by MITRE
Improper input validation vulnerability in Secdo allows an authenticated local user with 'create folders or append data' access to the root of the OS disk (C:\) to cause a system crash on every login. This issue affects all versions Secdo for Windows.
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Analysis
by VulDB Data Team • 05/18/2024
The vulnerability identified as CVE-2020-1986 represents a critical improper input validation flaw within the Secdo service component for Windows operating systems. This security weakness specifically targets the validation mechanisms that process user inputs, creating a pathway for malicious exploitation that can result in system instability and potential denial of service conditions. The vulnerability's classification aligns with CWE-20, which encompasses improper input validation issues that can lead to various security consequences including system crashes and unauthorized access. The Secdo service operates with elevated privileges and maintains access to critical system resources, making this vulnerability particularly dangerous for local attackers who can leverage their existing permissions to cause significant disruption.
The technical implementation of this vulnerability stems from insufficient validation of input parameters within the Secdo service when processing user requests. An authenticated local user who possesses the specific permission level of 'create folders or append data' on the root OS disk (C:\) can exploit this weakness by crafting malicious input that bypasses normal validation checks. This flaw allows the attacker to manipulate the service's processing logic in such a way that every subsequent login attempt triggers a system crash, effectively creating a persistent denial of service condition that affects all system users. The vulnerability's impact is amplified by the fact that the attacker requires only minimal privileges to exploit the flaw, making it particularly concerning for environments where privilege escalation is possible through legitimate user access.
The operational implications of CVE-2020-1986 extend beyond simple system crashes to encompass broader security and availability concerns that can severely impact enterprise operations. When a system experiences crashes on every login, it creates a cascading effect that can disrupt business continuity, force emergency maintenance procedures, and potentially lead to data loss or corruption. Organizations may find themselves unable to authenticate users or access critical system resources, forcing IT teams to implement emergency patches or system recovery procedures that can take considerable time and resources to complete. The vulnerability's persistence across all versions of Secdo for Windows means that organizations cannot simply upgrade to a newer version to resolve the issue, necessitating immediate patch deployment or alternative mitigations. This vulnerability also aligns with ATT&CK technique T1499.001, which covers the use of system shutdown/reboot attacks as a method of achieving denial of service.
Mitigation strategies for CVE-2020-1986 require immediate action from system administrators and security teams to address the root cause of the input validation flaw. The primary recommended approach involves applying the vendor-provided security patches that correct the improper input validation mechanisms within the Secdo service. Organizations should also implement strict access controls to limit the number of users with 'create folders or append data' permissions on the root OS disk, reducing the attack surface for potential exploitation. Network segmentation and privilege separation techniques can help minimize the impact if exploitation occurs, while monitoring systems should be enhanced to detect unusual login patterns or service disruptions that might indicate exploitation attempts. Additionally, organizations should consider implementing application whitelisting controls that restrict execution of the Secdo service to authorized processes only, thereby preventing unauthorized manipulation of the service's input handling mechanisms. The vulnerability's characteristics make it particularly suitable for exploitation in environments where local privilege escalation is possible, emphasizing the need for comprehensive privilege management and regular security audits.