A critical vulnerability in Windows LDAP (CVE-2024-49112) has been disclosed, revealing a remote code execution (RCE) flaw that affects Windows servers, particularly Domain Controllers (DCs). This vulnerability, which received a CVSS severity score of 9.8, was announced by Microsoft during its December 2024 Patch Tuesday update. Since Domain Controllers are responsible for managing authentication and user privileges in organizational networks, exploiting this flaw could allow attackers to compromise entire domains, making it a high-priority threat for enterprises.
The vulnerability stems from an integer overflow in LDAP-related code, which enables unauthenticated attackers to send specially crafted RPC calls to trigger malicious LDAP queries. This flaw could cause unpatched servers to crash or, more critically, allow attackers to execute arbitrary code within the context of the LDAP service. SafeBreach Labs has released a proof-of-concept (PoC) exploit named “LDAPNightmare” to demonstrate how attackers can exploit this flaw to crash vulnerable servers. The PoC shows that attackers can initiate an attack by sending DCE/RPC requests, ultimately causing the Local Security Authority Subsystem Service (LSASS) to crash and reboot the server.
Exploitation of this vulnerability is especially concerning as it could provide attackers with the ability to take control of critical domain environments. Windows Server 2019 and 2022 versions are particularly at risk, and organizations using these versions must take immediate action. Microsoft has already released a patch addressing the integer overflow issue, but unpatched systems remain vulnerable. To mitigate risks, enterprises are strongly encouraged to apply the December 2024 patch as soon as possible and begin monitoring for unusual DNS SRV queries, CLDAP referral responses, and DsrGetDcNameEx2 calls.
In light of the serious risks associated with CVE-2024-49112, organizations should not only apply the patch but also test their defenses using the available PoC tool from SafeBreach Labs. The tool can be accessed on GitHub, providing a valuable resource for testing system vulnerabilities. The timely release of the PoC highlights the urgency of addressing this critical flaw, and it underscores the importance of robust security practices and ongoing monitoring to protect critical network infrastructure from exploitation.
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