Description

Heap-based buffer overflow in Windows LDAP - Lightweight Directory Access Protocol allows an unauthorized attacker to execute code over a network.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-08-11T17:18:32.103Z",
  "pubdate": "2026-08-11T17:18:32.103Z",
  "executiveSummary": "A critical heap-based buffer overflow vulnerability exists in Windows LDAP (Lightweight Directory Access Protocol), posing severe security risks to enterprise environments utilizing affected Microsoft operating systems. This vulnerability allows an unauthorized remote attacker to achieve arbitrary code execution over the network without requiring user interaction or prior authentication.\nThe flaw resides within the processing logic of LDAP requests handled by the vulnerable component. By crafting malicious network packets and transmitting them to a target running the Lightweight Directory Access Protocol service, an adversary can corrupt heap memory structures. Successful exploitation compromises the integrity, confidentiality, and availability of the host system, granting the attacker the ability to execute arbitrary native code within the context of the service.\nGiven the network-exposed nature of LDAP services within Active Directory and standalone configurations, this vulnerability presents a high attack surface. Unauthorized remote exploitation capabilities elevate the risk profile significantly, potentially facilitating lateral movement, privilege escalation, and full domain compromise if domain controllers are targeted. Remediation requires prompt application of official vendor patches and strict adherence to network segmentation and boundary defense best practices.",
  "technicalDetails": "The vulnerability is a classic heap-based buffer overflow stemming from memory mismanagement within the Windows LDAP (Lightweight Directory Access Protocol) parsing routines. When the vulnerable component processes incoming LDAP packets over the network, it fails to adequately validate the size and boundaries of input data copied into dynamically allocated heap memory buffers. Specifically, improper bounds checking during the deserialization or parsing of specific protocol fields leads to a heap corruption condition where incoming data exceeds the allocated buffer dimensions.\nExploitation of this flaw requires an unauthorized network attacker to establish a connection to the target listening on the LDAP service port. The attack vector involves transmitting a maliciously crafted sequence of LDAP requests containing oversized payloads designed to overwrite adjacent heap metadata or function pointers. As the vulnerable parsing function writes data past the boundary of the target heap chunk, critical control data or application states are corrupted.\nUpon successful memory corruption, the instruction pointer or underlying execution flow can be hijacked, allowing the injected payload to execute arbitrary code with the privileges of the LDAP service process, typically operating with high system or network service privileges. Because the attack requires no authentication or user interaction, it can be fully automated and launched directly across the network against any exposed endpoint running the Lightweight Directory Access Protocol.\nThe post-exploitation impact includes complete system compromise, installation of persistent backdoors, and facilitation of credential harvesting or internal network reconnaissance. The attack flow relies entirely on network exposure, bypassing traditional endpoint controls if the protocol port is accessible through firewalls or internal VLANs."
}