CVE-2018-11219

Imagine Redis has a feature for running small Lua scripts, like a “programmable toolbox.” This bug is like a mistake in how the toolbox measures sizes—an attacker can feed it a specially crafted input so it stops checking limits correctly. That can let Redis crash, leak data, or potentially be taken over.

This matters if your business runs Redis (including embedded/packaged Redis) in versions before 3.2.12, 4.x before 4.0.10, or 5.x before 5.0 RC2. The findings say it is reachable over the network with no authentication and no user interaction, and it is considered reachable in the default configuration.

Reachability gate: only avoid risk if your Redis is already on a fixed version, or the vulnerable Lua subsystem is not present/enabled in the running build.

Treat this as urgent because attackers are able to trigger it remotely without authentication, and public exploits are available. Since it breaks bounds checking, the impact can go beyond a simple crash—up to full compromise—so you should upgrade on the earliest possible schedule.

Confirm exposure

1. Identify the exact Redis version running in production (not just what’s in your documentation).
2. Confirm that the Lua scripting subsystem/feature is enabled in your Redis deployment (the risk described is specifically in the Lua/struct library area).
3. Check network reachability to the Redis service: because the findings state it is network-reachable and unauthenticated, any exposed Redis port increases risk.

Upgrade to fixed versions

Upgrade Redis to one of the known fixed versions:

• Redis 3.2.12
• Redis 4.0.10
• Redis 5.0 RC2

Choose the fixed target that matches your currently running major version/branch, and upgrade within your operational constraints.

Temporary workaround (if you cannot patch immediately)

• Restrict network access to Redis so it is not reachable by unauthenticated users from the network (e.g., allowlist only known internal clients/VPN, close the port to the internet). This directly reduces the “unauthenticated remote trigger” risk described in the findings.

Verification after patch

1. Re-check the running Redis version to ensure it is the expected fixed release.
2. Validate that Redis and any dependent apps still work as normal.

What to monitor

• Redis crash/restart events and abnormal error logs after any remote traffic.
• Unusual inbound requests to Redis (especially if Redis is exposed to the broader network).

Note: KEV is not listed for this CVE in the provided findings.

CVE-2018-11219 (CWE-190) is an integer overflow in the Redis Lua subsystem’s struct library that causes failures in bounds checking. The findings state this can be triggered by a specific crafted input over the network by an unauthenticated attacker (no authentication, no user interaction). Outcomes described include server crash or arbitrary code execution via memory out-of-bounds access.

Exploitation status: public exploit available (1 known). KEV: not listed in CISA KEV. EPSS is provided as a prediction and is rising, but the findings do not indicate KEV-confirmed exploitation.

Fix: Redis releases before 3.2.12, 4.0.10, and 5.0 RC2 are affected; fixed versions are noted in the patch findings.