CVE-2025-46817
Description
An integer overflow present in the Redis Lua scripting engine that allows an authenticated client to submit a specially crafted Lua script (for example via EVAL/EVALSHA) that can trigger memory corruption and potentially lead to remote code execution within the Redis server process.
Statement
This is classified as Moderate because exploitation requires an authenticated client with permission to execute Lua scripts (for example via EVAL/EVALSHA) rather than an unauthenticated network attacker, narrowing the exposure to already trusted principals or compromised application identities. The flaw is an integer overflow in Lua script handling that can corrupt memory, but reliable code execution is non-trivial and there are no public proofs of concept or known in-the-wild exploits as of the initial advisories, which lowers immediate operational risk despite the theoretical impact. Practically, triggering a controlled overflow through the embedded Lua runtime adds exploit complexity, as the attacker must shape arithmetic and memory behavior inside Redis’s scripting environment to gain control flow, increasing the likelihood of crashes over deterministic RCE in typical configurations. Even in a worst case, the effect is within the Redis server process context rather than a guaranteed system-wide compromise, further reducing systemic blast radius if the service is not over-privileged.
This flaw exists only in the Redis server implementation;
Redis client libraries (Python, Node.js, Rust, etc.) are not affected by this vulnerability, and it only exists in the Redis server’s embedded Lua engine where scripts execute. Client libraries merely transmit EVAL/EVALSHA to the server.
Mitigation
No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.
To reduce the risk, restricting network access to trusted hosts, enforcing strong authentication and protected-mode, disabling or limiting Lua scripting where possible can be be benificial and apply least-privilege ACLs to reduce who can run scripting commands, keep instances non-public with firewalls/VPCs, and follow Redis hardening guidance to minimize exposure.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.8 | 8.8 | 7 |
| Attack Vector | Network | Network | Local |
| Attack Complexity | Low | Low | High |
| Privileges Required | Low | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | High | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Red Hat CVSS v3 Score Explanation
PR:L as exploitation requires an authenticated client with permission to execute Lua scripts (for example via EVAL/EVALSHA) rather than an unauthenticated network attacker, narrowing the exposure to already trusted principals or compromised application identities.
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (Memory); DoS: Instability
This weakness can generally lead to undefined behavior and therefore crashes. When the calculated result is used for resource allocation, this weakness can cause too many (or too few) resources to be allocated, possibly enabling crashes if the product requests more resources than can be provided.
Integrity
Technical Impact: Modify Memory
If the value in question is important to data (as opposed to flow), simple data corruption has occurred. Also, if the overflow/wraparound results in other conditions such as buffer overflows, further memory corruption may occur.
Confidentiality,Availability,Access Control
Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism
This weakness can sometimes trigger buffer overflows, which can be used to execute arbitrary code. This is usually outside the scope of the product's implicit security policy.
Availability,Other
Technical Impact: Alter Execution Logic; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)
If the overflow/wraparound occurs in a loop index variable, this could cause the loop to terminate at the wrong time - too early, too late, or not at all (i.e., infinite loops). With too many iterations, some loops could consume too many resources such as memory, file handles, etc., possibly leading to a crash or other DoS.
Access Control
Technical Impact: Bypass Protection Mechanism
If integer values are used in security-critical decisions, such as calculating quotas or allocation limits, integer overflows can be used to cause an incorrect security decision.
Frequently Asked Questions
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