CVE-2025-53716 in Windows
Summary
by MITRE • 08/12/2025
Null pointer dereference in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to deny service over a network.
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Analysis
by VulDB Data Team • 11/22/2025
The vulnerability identified as CVE-2025-53716 represents a critical null pointer dereference flaw within the Windows Local Security Authority Subsystem Service LSASS component. This issue specifically affects the authentication and authorization processes that are fundamental to Windows security infrastructure. The LSASS service operates as a critical system process responsible for validating user credentials and managing security policies across Windows domains. When an attacker successfully exploits this vulnerability, they can trigger a denial of service condition that disrupts the normal operation of the security subsystem.
The technical nature of this flaw stems from improper input validation within the LSASS service implementation. During normal operation, LSASS processes authentication requests from network clients and validates credentials against the local security database. The null pointer dereference occurs when the service attempts to access a memory location that has not been properly initialized or has been set to null. This condition typically arises when the service receives malformed or specially crafted authentication requests that exploit gaps in the validation logic. The vulnerability is particularly concerning because it requires only authorized network access to exploit, meaning attackers who already have legitimate network credentials can leverage this flaw to cause service disruption.
From an operational impact perspective, this vulnerability poses significant risks to enterprise environments where Windows domain controllers rely heavily on LSASS functionality for authentication services. When exploited successfully, the null pointer dereference causes the LSASS service to crash and restart automatically, resulting in temporary authentication failures for all network users. The service disruption can last from several seconds to minutes depending on system configuration and the specific exploitation method used. Organizations may experience cascading effects as authentication failures propagate through their network infrastructure, potentially affecting file servers, application servers, and other systems that depend on successful authentication to function properly. The vulnerability's network-based exploitation capability means that attackers can target these services from remote locations without requiring physical access to the affected systems.
The exploitation of CVE-2025-53716 aligns with several ATT&CK framework techniques including T1499.004 for network denial of service and T1566.002 for spearphishing with social engineering. This vulnerability can be categorized under CWE-476 which specifically addresses null pointer dereference conditions. The flaw represents a classic example of how authentication services can be targeted to create service disruption rather than direct privilege escalation or data compromise. Organizations should note that this vulnerability does not inherently provide access to additional system resources or data, but rather creates a mechanism for disrupting the availability of critical security services. The impact extends beyond simple service interruption as it can affect the overall security posture of an organization by making authentication services unreliable during critical periods.
Mitigation strategies for this vulnerability should focus on immediate patch management implementation as the primary defense mechanism. Microsoft typically releases security updates through regular monthly patches or emergency bulletins when critical vulnerabilities like this are discovered. Organizations should also implement network segmentation to limit access to domain controller services and employ monitoring solutions that can detect unusual LSASS service behavior or authentication request patterns. Additional protective measures include implementing authentication auditing and logging to track potential exploitation attempts, as well as maintaining redundant authentication services where possible to ensure continued availability during potential service disruptions. Network access controls should be configured to restrict unnecessary access to LSASS endpoints, and organizations should consider implementing intrusion detection systems that can identify exploitation attempts targeting this specific vulnerability pattern.