CVE-2025-6505 is a high-severity vulnerability affecting Progress Software's Hybrid Data Pipeline Server on Linux, specifically versions 4.6.2.3226 and below. The vulnerability arises from improper handling of OAuth client credentials during the OAuth handshake process. The server accepts client credentials from both HTTP headers and request parameters, allowing an attacker to combine credentials from different sources. This flaw can lead to unauthorized access and client impersonation, enabling attackers to bypass authentication controls and potentially gain elevated privileges or access sensitive data. The vulnerability impacts confidentiality, integrity, and availability, as attackers can impersonate legitimate clients and perform unauthorized actions within the system. The CVSS 3.1 score of 8.1 reflects the critical nature of this vulnerability, with network attack vector, no privileges required, no user interaction, and high impact on confidentiality, integrity, and availability. Although no known exploits are currently reported in the wild, the vulnerability's characteristics make it a significant risk if weaponized.

For European organizations, this vulnerability poses a substantial risk, especially for those relying on Progress Software's Hybrid Data Pipeline for data integration and management. Unauthorized access and impersonation can lead to data breaches, unauthorized data manipulation, and disruption of critical data workflows. Organizations in sectors such as finance, healthcare, manufacturing, and government, which often use such middleware solutions, could face regulatory penalties under GDPR if personal data is compromised. The ability to impersonate clients could also facilitate lateral movement within networks, increasing the risk of broader compromise. The vulnerability's network-exploitable nature means attackers can target exposed servers remotely, increasing the attack surface for European enterprises with internet-facing Hybrid Data Pipeline deployments.

To mitigate this vulnerability, organizations should immediately identify and inventory all instances of Progress Hybrid Data Pipeline Server in their environment, focusing on Linux deployments running version 4.6.2.3226 or earlier. Applying vendor patches or updates as soon as they become available is critical. In the absence of patches, organizations should implement strict network segmentation and firewall rules to restrict access to the Hybrid Data Pipeline servers, limiting exposure to trusted internal networks only. Additionally, reviewing and hardening OAuth client credential handling configurations can reduce risk; for example, disabling acceptance of credentials from multiple sources simultaneously if configurable. Monitoring and logging OAuth authentication attempts for anomalies can help detect exploitation attempts early. Employing multi-factor authentication (MFA) for client access where possible and conducting regular security assessments of the deployment environment will further reduce risk.