CVE-2026-79896 in BoKS Manager
Summary
by MITRE • 10/01/2026
Fortra BoKS Manager contains an out-of-bounds read vulnerability in the custom TLS ClientHello parser used by boks_portmux. A remote unauthenticated attacker can submit a malformed ClientHello and terminate boks_portmux. Although the daemon is normally restarted automatically, repeated requests can sustain the service interruption.
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Analysis
by VulDB Data Team • 10/01/2026
The identified security flaw resides within Fortra BoKS Manager, specifically affecting the custom Transport Layer Security client hello parser utilized by the boks_portmux component. This vulnerability constitutes an out-of-bounds read condition that arises when the application processes incoming network traffic containing a malformed TLS ClientHello message. The root cause of this issue is likely insufficient validation or bounds checking within the parsing logic responsible for interpreting the initial handshake parameters sent by connecting clients. When a remote, unauthenticated attacker submits a specially crafted packet with invalid data structures or length fields that exceed expected boundaries, the parser attempts to access memory locations outside the allocated buffer space. This type of error typically leads to undefined behavior in C-based applications, often resulting in process crashes or segmentation faults when the application tries to read from protected or non-existent memory addresses.
The operational impact of this vulnerability is primarily centered on service availability rather than data confidentiality or integrity at this stage. Because boks_portmux acts as a critical daemon for managing connections within the BoKS environment, its termination disrupts the ability of legitimate users and systems to authenticate and interact with the directory services managed by Fortra BoKS Manager. While the system architecture includes mechanisms to automatically restart the daemon upon failure, which mitigates immediate total service loss, this recovery mechanism introduces a significant risk of denial-of-service conditions. An attacker can exploit this flaw by sending repeated malformed requests in rapid succession. Each request triggers another crash and subsequent restart cycle, effectively creating a sustained interruption that prevents normal operations from resuming or functioning correctly during the downtime periods associated with process termination and initialization.
From a classification perspective, this vulnerability aligns closely with CWE-125, which describes Out-of-bounds Read vulnerabilities where software reads data past the end of a buffer. The exploitation technique falls under MITRE ATT&CK techniques related to Denial of Service, specifically those involving application layer protocol abuse or resource exhaustion through repeated triggering of failure states. Although the attacker does not gain direct code execution privileges in this scenario, the ability to consistently disrupt service availability represents a severe threat to business continuity and operational reliability for organizations relying on BoKS Manager for identity management tasks.
Mitigation strategies should focus on both immediate remediation and long-term architectural improvements. The most effective solution is to apply the vendor-provided patch or update that addresses the bounds checking logic within the TLS ClientHello parser. Until such a patch is available, network-level controls can be implemented to restrict access to the boks_portmux service ports exclusively from trusted IP ranges using firewall rules or access control lists. Additionally, deploying intrusion prevention systems configured with signatures for malformed TLS handshakes may help filter out malicious traffic before it reaches the vulnerable application layer. It is also advisable to review logging mechanisms to detect patterns of repeated connection attempts that exhibit characteristics of this exploitation vector, allowing for proactive blocking of source addresses exhibiting such behavior.