CVE-1999-1070 describes a buffer overflow vulnerability in the ping CGI program of the Xylogics Annex terminal service. This vulnerability arises when the application processes an excessively long query parameter, which causes the buffer allocated for this parameter to overflow. The overflow can lead to memory corruption, resulting in the application crashing and thus causing a denial of service (DoS) condition. The vulnerability is remotely exploitable without authentication, as the CGI program is accessible over the network. However, the impact is limited to availability, with no confidentiality or integrity compromise reported. The vulnerability was published in 1998, and no patches or fixes are available, indicating that the product may be obsolete or unsupported. The CVSS score is 5.0 (medium severity), reflecting the ease of exploitation (network accessible, no authentication) but limited impact (denial of service only). No known exploits have been reported in the wild, and the affected product is the Xylogics Annex terminal service, a specialized terminal server product used primarily in legacy network environments.

For European organizations, the primary impact of this vulnerability is the potential disruption of terminal services that rely on the Xylogics Annex product. Such disruption could affect operational continuity where these terminal servers are used to provide remote access to critical infrastructure or legacy systems. Although the vulnerability does not compromise data confidentiality or integrity, denial of service attacks could lead to downtime, impacting business operations, especially in sectors dependent on legacy terminal access such as manufacturing, utilities, or industrial control systems. Given the age of the vulnerability and the product, it is likely that many organizations have migrated away from this technology; however, any remaining deployments in Europe could face service interruptions if targeted. The lack of available patches means organizations must rely on compensating controls to mitigate risk.

Since no patches are available for this vulnerability, European organizations should consider the following specific mitigation strategies: 1) Identify and inventory any Xylogics Annex terminal servers in their environment to assess exposure. 2) Isolate these devices on segmented networks with strict access controls to limit exposure to untrusted networks, especially the internet. 3) Implement network-level filtering to block or restrict HTTP requests to the vulnerable CGI endpoint, particularly those containing long or suspicious query parameters. 4) Employ intrusion detection/prevention systems (IDS/IPS) with signatures or anomaly detection to monitor and block attempts to exploit this buffer overflow. 5) Where possible, replace or upgrade legacy terminal services with modern, supported alternatives that do not have known vulnerabilities. 6) Conduct regular security assessments and penetration tests focusing on legacy systems to identify and remediate similar risks. 7) Maintain robust incident response plans to quickly address any denial of service incidents affecting terminal services.