CVE-2021-32626 Lua scripts can overflow the heap-based Lua stack in Redis

2021-10-0417:30:11

CWE-122

CWE-787

GitHub_M

www.cve.org

redis

heap-based

lua

stack

overflow

cve-2021-32626

heap corruption

remote code execution

redis versions

lua scripting support

patching

workaround

acl commands

CVSS3

7.5

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

AI Score

Confidence

High

EPSS

0.023

Percentile

89.7%

JSON

Redis is an open source, in-memory database that persists on disk. In affected versions specially crafted Lua scripts executing in Redis can cause the heap-based Lua stack to be overflowed, due to incomplete checks for this condition. This can result with heap corruption and potentially remote code execution. This problem exists in all versions of Redis with Lua scripting support, starting from 2.6. The problem is fixed in versions 6.2.6, 6.0.16 and 5.0.14. For users unable to update an additional workaround to mitigate the problem without patching the redis-server executable is to prevent users from executing Lua scripts. This can be done using ACL to restrict EVAL and EVALSHA commands.

CNA Affected

[
  {
    "product": "redis",
    "vendor": "redis",
    "versions": [
      {
        "status": "affected",
        "version": ">= 6.2.0, < 6.2.6"
      },
      {
        "status": "affected",
        "version": ">= 6.0.0, < 6.0.16"
      },
      {
        "status": "affected",
        "version": ">= 2.6.0, < 5.0.14"
      }
    ]
  }
]