CVE-2011-1094 in kdelibs
Summary
by MITRE
kio/kio/tcpslavebase.cpp in KDE KSSL in kdelibs before 4.6.1 does not properly verify that the server hostname matches the domain name of the subject of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a certificate issued by a legitimate Certification Authority for an IP address, a different vulnerability than CVE-2009-2702.
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Analysis
by VulDB Data Team • 10/19/2021
The vulnerability described in CVE-2011-1094 represents a critical flaw in the KDE KSSL implementation within kdelibs version 4.6.1 and earlier. This security weakness resides in the kio/kio/tcpslavebase.cpp file where the SSL certificate validation process fails to properly verify that the server hostname matches the domain name contained in the X.509 certificate subject field. The flaw specifically impacts the SSL/TLS certificate verification mechanism used by KDE applications when establishing secure connections to remote servers through the KIO (KDE Internet Operations) framework.
The technical nature of this vulnerability stems from improper hostname verification during SSL certificate validation, which creates a path for man-in-the-middle attacks. Attackers can exploit this weakness by obtaining a legitimate SSL certificate from a trusted Certification Authority for an IP address or a different domain name than the target server. The certificate validation process in affected KDE versions does not adequately cross-reference the hostname being connected to with the subject alternative name or common name fields in the X.509 certificate, allowing attackers to present certificates that appear legitimate to the client application while actually connecting to malicious servers.
This vulnerability operates at the application layer and specifically affects KDE-based applications that utilize the KIO framework for network communications. The impact extends beyond individual applications to potentially compromise the entire KDE desktop environment's secure communication capabilities. When exploited, this flaw allows attackers to establish seemingly secure connections to malicious servers while the user believes they are connecting to legitimate services, enabling data interception, modification, and potential credential theft.
The operational consequences of CVE-2011-1094 are significant for any organization using KDE desktop environments with kdelibs versions prior to 4.6.1. Users may unknowingly establish secure connections to attacker-controlled servers, undermining the trust model that SSL/TLS certificates are designed to provide. This vulnerability particularly affects web browsing, email clients, and other network-dependent applications that rely on KDE's secure communication libraries. The flaw's similarity to CVE-2009-2702 indicates a persistent pattern in SSL certificate validation implementation issues within the KDE ecosystem, highlighting the importance of proper hostname verification in cryptographic implementations.
Organizations should immediately update to kdelibs version 4.6.1 or later to remediate this vulnerability. Additionally, system administrators should implement network monitoring to detect unusual certificate validation behavior and consider temporary network-level restrictions on SSL/TLS connections until full patching is completed. The vulnerability aligns with CWE-295, which specifically addresses improper certificate validation, and represents a technique commonly used in the MITM attack category as documented in the MITRE ATT&CK framework under T1041 for data encryption and T1566 for credential access through network infiltration.
Security teams should conduct comprehensive vulnerability assessments to identify all systems running affected KDE versions and ensure proper patch management procedures are in place. The remediation process should include not only updating kdelibs but also verifying that all KDE applications utilizing the KIO framework have been properly updated. Organizations should also consider implementing additional security controls such as certificate pinning for critical applications and network segmentation to limit the potential impact of successful exploitation attempts. The vulnerability demonstrates the critical importance of proper certificate validation implementation and serves as a reminder that cryptographic security relies not only on the strength of encryption algorithms but also on correct implementation of security protocols.