CVE-2022-0543 - Redis Lua Sandbox Escape Remote Code Execution (Debian/Ubuntu)

CVE-2022-0543 is a critical security vulnerability affecting Redis on Debian-based Linux distributions (including Debian and Ubuntu). It is caused by a packaging flaw that leads to a Lua sandbox escape, which can result in remote code execution (RCE) on the affected system.

Upstream Redis itself is not vulnerable — the issue is specific to how some Linux distributions packaged Redis and Lua.

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Severity

• CVSS Score: 10.0 (Critical)
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Impact: Full compromise of confidentiality, integrity, and availability

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Technical Description

Redis supports Lua scripting for server-side execution of scripts. In affected Debian/Ubuntu packages, Lua is dynamically linked in a way that breaks the intended sandboxing model.

This misconfiguration allows an attacker to:

• Break out of the Lua sandbox
• Access restricted system functionality
• Execute arbitrary system commands
• Potentially gain full control of the host running Redis

The root cause is a packaging difference:

• Upstream Redis: Lua is statically linked (safer sandbox isolation)
• Debian/Ubuntu Redis: Lua is dynamically linked (unsafe in this context)

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Affected Systems

• Debian Linux (specific Redis packages)
• Ubuntu Linux (affected versions prior to patched releases)
• Redis packages built using vulnerable Debian packaging

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Impact

If exploited successfully, an attacker can:

• Execute arbitrary code on the server
• Compromise sensitive data stored in Redis
• Escalate to full system compromise
• Pivot into internal networks (if Redis is exposed)

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Exploitation Requirements

• Ability to interact with Redis (network access)
• Ability to execute or inject Lua scripts into Redis
• No authentication is required in some misconfigured deployments

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Mitigation

Recommended Fix

• Update Redis packages from official security repositories:
  • Debian Security Advisory: DSA-5081
  • Ubuntu security updates (fixed in patched releases)

Immediate Actions

• Upgrade Redis to patched version
• Restrict Redis access to trusted networks only
• Bind Redis to localhost if not externally required
• Enable authentication (requirepass)
• Disable Lua scripting if not needed

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Detection Tips

Look for:

• Redis instances exposed to public networks
• Outdated Redis versions on Debian/Ubuntu
• Unexpected system calls from Redis process
• Lua script execution patterns in Redis logs

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References

• https://nvd.nist.gov/vuln/detail/CVE-2022-0543
• https://www.debian.org/security/2022/dsa-5081
• https://bugs.debian.org/1005787
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog

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Summary

CVE-2022-0543 is a critical Redis vulnerability caused by Debian packaging issues, enabling a Lua sandbox escape that can lead to full remote code execution. It is actively tracked in vulnerability databases and should be patched immediately on affected systems.

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Disclaimer

This document includes high level technical information about CVE-2022-0543 for educational and defensive security purposes.

Public proof-of-concept (PoC) exploits for this vulnerability exist and have been circulated within the security research and penetration testing community. These PoC implementations demonstrate how the Lua sandbox escape can be achieved under specific conditions in vulnerable environments.

However, the inclusion or discussion of such exploit material in this repository is strictly for understanding attack mechanics, improving defensive security posture, and ensuring proper patching and mitigation. It is not intended to facilitate unauthorized access, exploitation of systems, or malicious activity of any kind.

Users are strongly advised to only test vulnerabilities in controlled, authorized lab environments and to ensure all systems are properly patched and secured.