CVE-1999-0813 is a high-severity local privilege escalation vulnerability found in the cfingerd daemon, a finger protocol server implementation from the infodrom project. The vulnerability arises when cfingerd is configured with the ALLOW_EXECUTION option enabled. Under this configuration, cfingerd executes programs on behalf of users but fails to properly drop its elevated privileges before doing so. As a result, a local attacker can exploit this flaw to execute arbitrary code with root privileges, effectively gaining full control over the affected system. The vulnerability was disclosed in 1999 and has a CVSS v2 base score of 7.2, reflecting its high impact on confidentiality, integrity, and availability. The attack vector is local (AV:L), requiring low attack complexity (AC:L) and no authentication (Au:N). Exploiting this vulnerability allows complete compromise of the system, including unauthorized access to sensitive data and the ability to disrupt or manipulate system operations. Although no patches are currently available, the vulnerability is well-documented and can be mitigated by disabling the ALLOW_EXECUTION option or removing cfingerd entirely, as the finger protocol is largely obsolete and rarely needed in modern environments.

For European organizations, the impact of this vulnerability can be significant if cfingerd is still in use on legacy systems or specialized environments. Successful exploitation results in local attackers gaining root privileges, which can lead to full system compromise, data breaches, and disruption of critical services. This is particularly concerning for organizations with sensitive or regulated data, such as financial institutions, healthcare providers, and government agencies. The vulnerability's local attack vector means that attackers must already have some form of access to the system, but once inside, they can escalate privileges and move laterally or persist undetected. Given the age of the vulnerability, it is unlikely to be exploited in modern, well-maintained environments; however, legacy systems or poorly maintained infrastructure in European organizations could still be at risk. The lack of available patches increases the risk for these environments, necessitating alternative mitigation strategies.

1. Disable the ALLOW_EXECUTION option in cfingerd configuration to prevent execution of arbitrary programs with elevated privileges. 2. Remove or uninstall cfingerd entirely, as the finger protocol is obsolete and rarely necessary in modern networks. 3. Restrict local user access to systems running cfingerd to trusted personnel only, minimizing the risk of local exploitation. 4. Implement strict access controls and monitoring on legacy systems that may still run cfingerd to detect unauthorized activities promptly. 5. Consider migrating legacy services to modern, supported alternatives that do not have known privilege escalation vulnerabilities. 6. Conduct regular security audits and vulnerability assessments to identify and remediate outdated services and configurations. 7. Employ host-based intrusion detection systems (HIDS) to monitor for suspicious privilege escalation attempts.