CVE-2026-77654: Horizon Security Analyzer Privilege Escalation

CVE-2026-77654 Overview

CVE-2026-77654 is an improper privilege management vulnerability [CWE-266] affecting Horizon Security Analyzer, formerly known as AlgoSec Firewall Analyzer, on Linux 64-bit systems. A local authenticated user can escalate privileges by abusing parameters of a command approved in the sudoers file. The flaw enables parameter injection and privilege escalation to a higher-privileged context. Affected releases include Horizon Security Analyzer versions A33.10, A33.20, and A33.30. According to the AlgoSec Tech Note on CVE-2026-77654, the issue requires local command-line access and user interaction.

Critical Impact
An authenticated local user can escalate privileges and inject parameters into a sudo-approved command, compromising the integrity and availability of the host running Horizon Security Analyzer.

Affected Products

Horizon Security Analyzer A33.10 (Linux, 64-bit)
Horizon Security Analyzer A33.20 (Linux, 64-bit)
Horizon Security Analyzer A33.30 (Linux, 64-bit)

Discovery Timeline

2026-09-08 - CVE-2026-77654 published to NVD
2026-09-08 - Last updated in NVD database

Technical Details for CVE-2026-77654

Vulnerability Analysis

The vulnerability resides in how Horizon Security Analyzer configures sudo-approved commands in /etc/sudoers. A command allowed through sudo accepts user-controlled parameters that are not sufficiently constrained. A local user with shell access can supply crafted arguments that alter the command's execution context. This allows the attacker to execute code or invoke additional commands under elevated privileges. The exploitation path requires local access and user interaction, but no prior high-privilege role on the target host.

Root Cause

The root cause is improper privilege management [CWE-266] in the sudoers configuration shipped with Horizon Security Analyzer versions A33.10 through A33.30. The approved command entry grants execution rights without restricting or validating parameters that influence what the command ultimately runs. Parameter injection converts a narrow, intended privilege delegation into an arbitrary elevation primitive.

Attack Vector

An attacker requires local shell access as a low-privileged user on the Linux appliance. The attacker invokes the sudo-approved command with maliciously crafted parameters that inject additional arguments, options, or command constructs. The elevated process then performs actions chosen by the attacker, resulting in privilege escalation. Refer to the AlgoSec Tech Note on CVE-2026-77654 for vendor-specific details on the affected command and remediation guidance.

Detection Methods for CVE-2026-77654

Indicators of Compromise

Unexpected entries in /var/log/auth.log or /var/log/secure showing sudo invocations of the Horizon Security Analyzer approved command with unusual parameter strings.
Child processes spawned by the sudo-approved command that do not match expected binaries (for example, shells, interpreters, or system utilities).
New or modified files in root-owned directories following sudo invocations by non-administrative accounts.

Detection Strategies

Audit sudo command execution using auditd rules targeting the specific binary listed in the Horizon Security Analyzer sudoers configuration.
Correlate low-privileged account logins with subsequent sudo calls that produce root-owned process trees.
Baseline expected parameter patterns for the approved command and alert on deviations, such as shell metacharacters, path traversal, or option flags not used operationally.

Monitoring Recommendations

Forward auth.log, secure, and auditd events to a centralized logging or SIEM platform for retention and correlation.
Enable process-tree telemetry on the Horizon Security Analyzer host to capture parent-child relationships spawned via sudo.
Alert on any modification to /etc/sudoers or files under /etc/sudoers.d/ outside of change-management windows.

How to Mitigate CVE-2026-77654

Immediate Actions Required

Restrict command-line and SSH access to the Horizon Security Analyzer host to a minimal set of trusted administrators.
Review /etc/sudoers and /etc/sudoers.d/ for the affected approved command and remove or tighten entries pending a patched release.
Rotate credentials for any local accounts that had access to the appliance prior to remediation.

Patch Information

Refer to the AlgoSec Tech Note on CVE-2026-77654 for vendor-supplied patch availability and upgrade instructions for Horizon Security Analyzer A33.10, A33.20, and A33.30.

Workarounds

Remove the affected entry from the sudoers configuration if operationally feasible, or replace it with a narrowly scoped alternative that hardcodes parameters.
Enforce parameter allow-lists using sudo's Cmnd_Alias with fully qualified command lines instead of wildcard arguments.
Limit membership in any group granted sudo rights on the Horizon Security Analyzer appliance and require multi-factor authentication for interactive logins.

bash

# Example: tighten a sudoers entry to a fully specified command with no wildcards
# Replace the permissive entry:
#   %hsa_ops ALL=(root) NOPASSWD: /opt/algosec/bin/example_tool *
# With a fixed-argument entry:
%hsa_ops ALL=(root) NOPASSWD: /opt/algosec/bin/example_tool --safe-mode --config /etc/algosec/example.conf