CVE-1999-0808 in DHCP Client
Summary
by MITRE
Multiple buffer overflows in ISC DHCP Distribution server (dhcpd) 1.0 and 2.0 allow a remote attacker to cause a denial of service (crash) and possibly execute arbitrary commands via long options.
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Analysis
by VulDB Data Team • 04/20/2026
The vulnerability identified as CVE-1999-0808 represents a critical security flaw in the Internet Systems Consortium DHCP Distribution server version 1.0 and 2.0. This issue manifests as multiple buffer overflow conditions that occur when the dhcpd server processes malformed or excessively long option parameters sent by remote clients. The vulnerability exists within the server's handling of DHCP options, which are used to convey configuration parameters to DHCP clients during the network configuration process. Buffer overflows of this nature typically arise when programs write more data to a fixed-length memory buffer than it can accommodate, leading to memory corruption that can be exploited by malicious actors.
The technical implementation of this vulnerability stems from inadequate input validation within the dhcpd server's option processing routines. When the server receives DHCP packets containing overly long option values, it fails to properly bounds-check the incoming data before copying it into fixed-size internal buffers. This lack of proper validation creates opportunities for attackers to craft specially malformed DHCP packets that exceed buffer capacity, causing the server process to crash or potentially execute arbitrary code. The vulnerability affects the core DHCP server functionality and operates at the network protocol level where DHCP transactions occur between clients and servers.
The operational impact of CVE-1999-0808 extends beyond simple denial of service conditions to potentially enable remote code execution, making it particularly dangerous in network environments where DHCP servers are critical infrastructure components. When exploited, the buffer overflow conditions can cause the dhcpd process to terminate unexpectedly, resulting in network disruption as clients lose the ability to obtain network configuration information. In more severe cases, attackers may be able to inject and execute malicious code within the context of the dhcpd process, potentially compromising the entire network infrastructure or gaining unauthorized access to systems relying on the affected DHCP server for network configuration.
Mitigation strategies for this vulnerability involve immediate patching of affected dhcpd server installations to versions that properly implement input validation and bounds checking for DHCP options. System administrators should also implement network monitoring to detect unusual DHCP traffic patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and relates to ATT&CK technique T1059.007 for command and scripting interpreter execution. Organizations should also consider implementing network segmentation and access controls to limit exposure of DHCP servers to untrusted networks, while maintaining regular vulnerability assessments to identify similar issues in other network infrastructure components.