CVE-2026-27208: Bleon API Gateway Deploy RCE Vulnerability

CVE-2026-27208 Overview

CVE-2026-27208 is a vulnerability affecting the bleon-ethical/api-gateway-deploy API gateway deployment tool. Version 1.0.0 is vulnerable to an attack chain involving OS Command Injection and Privilege Escalation. This flaw allows an attacker to execute arbitrary commands with root privileges within the container, potentially leading to a container escape and unauthorized infrastructure modifications.

Critical Impact

Attackers can chain OS command injection with privilege escalation to gain root access within containers, potentially escaping the container and modifying underlying infrastructure.

Affected Products

• bleon-ethical api-gateway-deploy version 1.0.0

Discovery Timeline

• 2026-02-24 - CVE CVE-2026-27208 published to NVD
• 2026-02-26 - Last updated in NVD database

Technical Details for CVE-2026-27208

Vulnerability Analysis

This vulnerability represents a dangerous attack chain combining OS Command Injection (CWE-78) with Privilege Escalation capabilities. The flaw exists in the entrypoint.sh script of the api-gateway-deploy container, where insufficient input sanitization allows attackers to inject arbitrary system commands. Because the container runs with root privileges, these injected commands execute with elevated permissions.

The attack requires local access but has low complexity once an attacker gains initial access to the container environment. Successful exploitation results in complete compromise of confidentiality, integrity, and availability within the container context, with the potential to escape the container boundary and affect the host infrastructure.

Root Cause

The root cause stems from improper input sanitization in the entrypoint.sh script combined with the container running as root. The lack of secure delimiters in the entrypoint script allows specially crafted input to break out of expected execution contexts and inject malicious commands. Additionally, the Dockerfile's failure to enforce a non-root user amplifies the impact, granting any injected commands full root privileges.

Attack Vector

The attack vector is local (AV:L), meaning an attacker must have prior access to the container environment. The attack chain proceeds as follows:

1. The attacker identifies unsanitized input parameters processed by entrypoint.sh
2. Malicious input containing shell metacharacters or command separators is crafted
3. When processed, the injected commands execute with root privileges
4. The attacker can then escalate further, potentially escaping the container to the host system

The vulnerability mechanism exploits improper handling of user-controlled input in shell scripts. The entrypoint.sh script processes parameters without proper validation, allowing shell metacharacters to be interpreted as command separators. This enables command chaining attacks where additional arbitrary commands are appended to legitimate operations. For detailed technical information, see the GitHub Security Advisory.

Detection Methods for CVE-2026-27208

Indicators of Compromise

• Unexpected process spawns within api-gateway-deploy containers, especially shells (/bin/sh, /bin/bash)
• Log entries showing unusual command sequences or shell metacharacters in entrypoint parameters
• Modifications to container filesystems or unexpected outbound network connections
• Evidence of user creation or permission changes within the container

Detection Strategies

• Monitor container logs for command injection patterns including shell metacharacters (;, |, &&, ||, `)
• Implement runtime security monitoring to detect anomalous process execution within containers
• Use container image scanning to identify deployments of vulnerable version 1.0.0
• Deploy network monitoring to detect unusual egress traffic from affected containers

Monitoring Recommendations

• Enable comprehensive audit logging for all api-gateway-deploy container instances
• Implement real-time alerting for root-level command execution within containers
• Monitor for container escape indicators such as access to /proc, /sys, or Docker socket
• Track changes to infrastructure configurations that may indicate post-exploitation activity

How to Mitigate CVE-2026-27208

Immediate Actions Required

• Upgrade bleon-ethical/api-gateway-deploy to version 1.0.1 or later immediately
• Audit all running instances to identify deployments using the vulnerable 1.0.0 version
• Review infrastructure for signs of compromise if version 1.0.0 has been deployed
• Implement network segmentation to limit potential blast radius of container compromises

Patch Information

The vendor has addressed this vulnerability in version 1.0.1. The fix implements:

• Strict input sanitization in entrypoint.sh to prevent command injection
• Secure delimiters to properly handle input parameters
• Non-root user enforcement (appuser) in the Dockerfile to limit privilege escalation impact
• Mandatory security quality gates to prevent similar issues in future releases

For patch details, see the GitHub Security Release.

Workarounds

• If immediate upgrade is not possible, restrict network access to affected containers
• Implement additional container runtime security controls to detect and block command injection attempts
• Run containers with read-only root filesystems where feasible to limit post-exploitation options
• Apply the principle of least privilege by manually modifying Dockerfiles to run as non-root until upgrade is complete

# Temporary workaround: Run container as non-root user
# Add to your docker run command
docker run --user 1000:1000 bleon-ethical/api-gateway-deploy:1.0.0

# Or modify your Dockerfile to add a non-root user
# RUN adduser -D appuser && chown -R appuser /app
# USER appuser