Vulnerability from bitnami_vulndb
Published
2025-04-25 07:24
Modified
2025-09-11 06:09
Summary
Redis DoS Vulnerability due to unlimited growth of output buffers abused by unauthenticated client
Details

Redis is an open source, in-memory database that persists on disk. In versions starting at 2.6 and prior to 7.4.3, An unauthenticated client can cause unlimited growth of output buffers, until the server runs out of memory or is killed. By default, the Redis configuration does not limit the output buffer of normal clients (see client-output-buffer-limit). Therefore, the output buffer can grow unlimitedly over time. As a result, the service is exhausted and the memory is unavailable. When password authentication is enabled on the Redis server, but no password is provided, the client can still cause the output buffer to grow from "NOAUTH" responses until the system will run out of memory. This issue has been patched in version 7.4.3. An additional workaround to mitigate this problem without patching the redis-server executable is to block access to prevent unauthenticated users from connecting to Redis. This can be done in different ways. Either using network access control tools like firewalls, iptables, security groups, etc, or enabling TLS and requiring users to authenticate using client side certificates.

To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "redis",
        "purl": "pkg:bitnami/redis"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.0"
            },
            {
              "fixed": "6.2.18"
            },
            {
              "introduced": "7.0.0"
            },
            {
              "fixed": "7.2.8"
            },
            {
              "introduced": "7.3.0"
            },
            {
              "fixed": "6.2.18"
            },
            {
              "introduced": "7.2.0"
            },
            {
              "fixed": "7.2.8"
            },
            {
              "introduced": "7.4.0"
            },
            {
              "fixed": "7.4.3"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "type": "CVSS_V3"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-21605"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:redis:redis:*:*:*:*:*:*:*:*"
    ],
    "severity": "High"
  },
  "details": "Redis is an open source, in-memory database that persists on disk. In versions starting at 2.6 and prior to 7.4.3, An unauthenticated client can cause unlimited growth of output buffers, until the server runs out of memory or is killed. By default, the Redis configuration does not limit the output buffer of normal clients (see client-output-buffer-limit). Therefore, the output buffer can grow unlimitedly over time. As a result, the service is exhausted and the memory is unavailable. When password authentication is enabled on the Redis server, but no password is provided, the client can still cause the output buffer to grow from \"NOAUTH\" responses until the system will run out of memory. This issue has been patched in version 7.4.3. An additional workaround to mitigate this problem without patching the redis-server executable is to block access to prevent unauthenticated users from connecting to Redis. This can be done in different ways. Either using network access control tools like firewalls, iptables, security groups, etc, or enabling TLS and requiring users to authenticate using client side certificates.",
  "id": "BIT-redis-2025-21605",
  "modified": "2025-09-11T06:09:54.070Z",
  "published": "2025-04-25T07:24:43.793Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/redis/redis/releases/tag/7.4.3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/redis/redis/security/advisories/GHSA-r67f-p999-2gff"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-21605"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00014.html"
    },
    {
      "type": "WEB",
      "url": "https://github.com/valkey-io/valkey/releases/tag/8.1.1"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "Redis DoS Vulnerability due to unlimited growth of output buffers abused by unauthenticated client"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.