CVE-2025-14905 in 389-ds-base
Summary
by MITRE • 02/23/2026
A flaw was found in the 389-ds-base server. A heap buffer overflow vulnerability exists in the `schema_attr_enum_callback` function within the `schema.c` file. This occurs because the code incorrectly calculates the buffer size by summing alias string lengths without accounting for additional formatting characters. When a large number of aliases are processed, this oversight can lead to a heap overflow, potentially allowing a remote attacker to cause a Denial of Service (DoS) or achieve Remote Code Execution (RCE).
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Analysis
by VulDB Data Team • 02/27/2026
The vulnerability identified as CVE-2025-14905 resides within the 389-ds-base server, a critical component of the 389 Directory Server ecosystem that provides directory services for enterprise environments. This server implementation handles schema management and attribute enumeration operations that are fundamental to directory service functionality. The flaw manifests in the schema_attr_enum_callback function located in the schema.c source file, representing a significant security concern given the server's role in managing identity and access control within organizational networks. The vulnerability's presence in core schema processing logic means it could potentially affect all directory service operations that rely on attribute enumeration and schema validation.
The technical root cause of this heap buffer overflow stems from an incorrect buffer size calculation within the schema_attr_enum_callback function. Specifically, the implementation fails to properly account for formatting characters when summing the lengths of alias strings during schema attribute processing. This miscalculation occurs when the code attempts to construct a formatted output string that includes multiple aliases, where each alias string must be properly sized to accommodate not just the alias content but also the necessary delimiters, separators, and formatting characters that delineate individual aliases within the final constructed buffer. When processing a large number of aliases, this cumulative error in buffer sizing can result in an overflow condition where data written to the heap buffer exceeds its allocated boundaries.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable remote code execution, making it a critical concern for enterprise security infrastructure. A remote attacker capable of submitting specially crafted schema attribute data could trigger the buffer overflow condition during normal directory service operations. The heap overflow could result in memory corruption that might allow attackers to execute arbitrary code on the vulnerable server with the privileges of the directory service process. This represents a severe escalation from basic DoS conditions, as the vulnerability could be exploited to compromise entire directory service environments, potentially affecting authentication systems, user management, and access control mechanisms that depend on the 389 Directory Server infrastructure.
Organizations should prioritize immediate mitigation strategies including applying vendor-provided patches or updates to address the buffer overflow in the schema_attr_enum_callback function. System administrators should also consider implementing network segmentation and access controls to limit exposure of directory services to untrusted networks. Monitoring for unusual schema processing activities or malformed attribute requests could help detect potential exploitation attempts. The vulnerability aligns with CWE-121 heap-based buffer overflow classification and represents a potential ATT&CK technique under T1190 for exploitation of remote services. Security teams should also review their directory service configurations to ensure that unnecessary schema modification capabilities are restricted, reducing the attack surface for potential exploitation. Given the nature of directory services as foundational infrastructure components, organizations should conduct thorough vulnerability assessments across their entire directory service ecosystem to identify any similar patterns in buffer handling across related components.