UBUNTU-CVE-2025-21605 (CVE-2025-21605)
Vulnerability from osv_ubuntu – Published: 2025-04-23 16:15 – Updated: 2026-10-17 09:30 – Source websiteRedis 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.
{
"affected": [
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "redis-server",
"binary_version": "2:2.8.4-2ubuntu0.2+esm5"
},
{
"binary_name": "redis-tools",
"binary_version": "2:2.8.4-2ubuntu0.2+esm5"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:14.04:LTS",
"name": "redis",
"purl": "pkg:deb/ubuntu/redis@2:2.8.4-2ubuntu0.2+esm5?arch=source\u0026distro=esm-infra-legacy/trusty"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2:2.6.13-1",
"2:2.6.16-3",
"2:2.8.0-1",
"2:2.8.2-1",
"2:2.8.4-2",
"2:2.8.4-2ubuntu0.2",
"2:2.8.4-2ubuntu0.2+esm1",
"2:2.8.4-2ubuntu0.2+esm2",
"2:2.8.4-2ubuntu0.2+esm3",
"2:2.8.4-2ubuntu0.2+esm4",
"2:2.8.4-2ubuntu0.2+esm5"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "redis-sentinel",
"binary_version": "2:3.0.6-1ubuntu0.4+esm5"
},
{
"binary_name": "redis-server",
"binary_version": "2:3.0.6-1ubuntu0.4+esm5"
},
{
"binary_name": "redis-tools",
"binary_version": "2:3.0.6-1ubuntu0.4+esm5"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:16.04:LTS",
"name": "redis",
"purl": "pkg:deb/ubuntu/redis@2:3.0.6-1ubuntu0.4+esm5?arch=source\u0026distro=esm-apps/xenial"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2:3.0.3-3",
"2:3.0.5-1",
"2:3.0.5-2",
"2:3.0.5-3",
"2:3.0.5-4",
"2:3.0.6-1",
"2:3.0.6-1ubuntu0.2",
"2:3.0.6-1ubuntu0.3",
"2:3.0.6-1ubuntu0.4",
"2:3.0.6-1ubuntu0.4+esm1",
"2:3.0.6-1ubuntu0.4+esm2",
"2:3.0.6-1ubuntu0.4+esm3",
"2:3.0.6-1ubuntu0.4+esm4",
"2:3.0.6-1ubuntu0.4+esm5"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "redis",
"binary_version": "5:4.0.9-1ubuntu0.2+esm7"
},
{
"binary_name": "redis-sentinel",
"binary_version": "5:4.0.9-1ubuntu0.2+esm7"
},
{
"binary_name": "redis-server",
"binary_version": "5:4.0.9-1ubuntu0.2+esm7"
},
{
"binary_name": "redis-tools",
"binary_version": "5:4.0.9-1ubuntu0.2+esm7"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:18.04:LTS",
"name": "redis",
"purl": "pkg:deb/ubuntu/redis@5:4.0.9-1ubuntu0.2+esm7?arch=source\u0026distro=esm-apps/bionic"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"4:4.0.1-7",
"4:4.0.2-6",
"4:4.0.2-9",
"5:4.0.5-1",
"5:4.0.6-1",
"5:4.0.6-2",
"5:4.0.7-1",
"5:4.0.8-1",
"5:4.0.8-2",
"5:4.0.9-1",
"5:4.0.9-1ubuntu0.1",
"5:4.0.9-1ubuntu0.2",
"5:4.0.9-1ubuntu0.2+esm2",
"5:4.0.9-1ubuntu0.2+esm3",
"5:4.0.9-1ubuntu0.2+esm4",
"5:4.0.9-1ubuntu0.2+esm5",
"5:4.0.9-1ubuntu0.2+esm6",
"5:4.0.9-1ubuntu0.2+esm7"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "redis",
"binary_version": "5:5.0.7-2ubuntu0.1+esm4"
},
{
"binary_name": "redis-sentinel",
"binary_version": "5:5.0.7-2ubuntu0.1+esm4"
},
{
"binary_name": "redis-server",
"binary_version": "5:5.0.7-2ubuntu0.1+esm4"
},
{
"binary_name": "redis-tools",
"binary_version": "5:5.0.7-2ubuntu0.1+esm4"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:20.04:LTS",
"name": "redis",
"purl": "pkg:deb/ubuntu/redis@5:5.0.7-2ubuntu0.1+esm4?arch=source\u0026distro=esm-apps/focal"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"5:5.0.5-2build1",
"5:5.0.6-1",
"5:5.0.7-1",
"5:5.0.7-2",
"5:5.0.7-2ubuntu0.1~esm1",
"5:5.0.7-2ubuntu0.1",
"5:5.0.7-2ubuntu0.1+esm1",
"5:5.0.7-2ubuntu0.1+esm2",
"5:5.0.7-2ubuntu0.1+esm3",
"5:5.0.7-2ubuntu0.1+esm4"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "redis",
"binary_version": "5:6.0.16-1ubuntu1.2+esm1"
},
{
"binary_name": "redis-sentinel",
"binary_version": "5:6.0.16-1ubuntu1.2+esm1"
},
{
"binary_name": "redis-server",
"binary_version": "5:6.0.16-1ubuntu1.2+esm1"
},
{
"binary_name": "redis-tools",
"binary_version": "5:6.0.16-1ubuntu1.2+esm1"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:22.04:LTS",
"name": "redis",
"purl": "pkg:deb/ubuntu/redis@5:6.0.16-1ubuntu1.2+esm1?arch=source\u0026distro=esm-apps/jammy"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"5:6.0.15-1",
"5:6.0.16-1",
"5:6.0.16-1build1",
"5:6.0.16-1ubuntu1",
"5:6.0.16-1ubuntu1+esm1",
"5:6.0.16-1ubuntu1+esm2",
"5:6.0.16-1ubuntu1.1",
"5:6.0.16-1ubuntu1.1+esm1",
"5:6.0.16-1ubuntu1.2",
"5:6.0.16-1ubuntu1.2+esm1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "redis",
"binary_version": "5:7.0.15-1ubuntu0.24.04.5"
},
{
"binary_name": "redis-sentinel",
"binary_version": "5:7.0.15-1ubuntu0.24.04.5"
},
{
"binary_name": "redis-server",
"binary_version": "5:7.0.15-1ubuntu0.24.04.5"
},
{
"binary_name": "redis-tools",
"binary_version": "5:7.0.15-1ubuntu0.24.04.5"
}
]
},
"package": {
"ecosystem": "Ubuntu:24.04:LTS",
"name": "redis",
"purl": "pkg:deb/ubuntu/redis@5:7.0.15-1ubuntu0.24.04.5?arch=source\u0026distro=noble"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"5:7.0.12-1",
"5:7.0.14-1",
"5:7.0.14-2",
"5:7.0.15-1",
"5:7.0.15-1build1",
"5:7.0.15-1build2",
"5:7.0.15-1ubuntu0.24.04.1",
"5:7.0.15-1ubuntu0.24.04.2",
"5:7.0.15-1ubuntu0.24.04.3",
"5:7.0.15-1ubuntu0.24.04.4",
"5:7.0.15-1ubuntu0.24.04.5"
]
},
{
"ecosystem_specific": {
"availability": "No subscription required",
"binaries": [
{
"binary_name": "valkey-redis-compat",
"binary_version": "7.2.11+dfsg1-0ubuntu0.2"
},
{
"binary_name": "valkey-sentinel",
"binary_version": "7.2.11+dfsg1-0ubuntu0.2"
},
{
"binary_name": "valkey-server",
"binary_version": "7.2.11+dfsg1-0ubuntu0.2"
},
{
"binary_name": "valkey-tools",
"binary_version": "7.2.11+dfsg1-0ubuntu0.2"
}
]
},
"package": {
"ecosystem": "Ubuntu:24.04:LTS",
"name": "valkey",
"purl": "pkg:deb/ubuntu/valkey@7.2.11+dfsg1-0ubuntu0.2?arch=source\u0026distro=noble"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "7.2.11+dfsg1-0ubuntu0.2"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"7.2.5+dfsg1-2ubuntu4~24.04.1",
"7.2.7+dfsg1-0ubuntu0.24.04.1",
"7.2.8+dfsg1-0ubuntu0.24.04.1",
"7.2.8+dfsg1-0ubuntu0.24.04.2",
"7.2.8+dfsg1-0ubuntu0.24.04.3",
"7.2.10+dfsg1-0ubuntu0.1",
"7.2.11+dfsg1-0ubuntu0.1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "redict",
"binary_version": "7.3.5+ds-1ubuntu0.2"
},
{
"binary_name": "redict-sentinel",
"binary_version": "7.3.5+ds-1ubuntu0.2"
},
{
"binary_name": "redict-server",
"binary_version": "7.3.5+ds-1ubuntu0.2"
},
{
"binary_name": "redict-tools",
"binary_version": "7.3.5+ds-1ubuntu0.2"
}
]
},
"package": {
"ecosystem": "Ubuntu:25.10",
"name": "redict",
"purl": "pkg:deb/ubuntu/redict@7.3.5+ds-1ubuntu0.2?arch=source\u0026distro=questing"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"7.3.2+ds-1",
"7.3.5+ds-1",
"7.3.5+ds-1ubuntu0.1",
"7.3.5+ds-1ubuntu0.2"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "redict",
"binary_version": "7.3.6+ds-2build1"
},
{
"binary_name": "redict-sentinel",
"binary_version": "7.3.6+ds-2build1"
},
{
"binary_name": "redict-server",
"binary_version": "7.3.6+ds-2build1"
},
{
"binary_name": "redict-tools",
"binary_version": "7.3.6+ds-2build1"
}
]
},
"package": {
"ecosystem": "Ubuntu:26.10",
"name": "redict",
"purl": "pkg:deb/ubuntu/redict@7.3.6+ds-2build1?arch=source\u0026distro=stonking"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"7.3.6+ds-1",
"7.3.6+ds-2",
"7.3.6+ds-2build1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "redict",
"binary_version": "7.3.6+ds-1"
},
{
"binary_name": "redict-sentinel",
"binary_version": "7.3.6+ds-1"
},
{
"binary_name": "redict-server",
"binary_version": "7.3.6+ds-1"
},
{
"binary_name": "redict-tools",
"binary_version": "7.3.6+ds-1"
}
]
},
"package": {
"ecosystem": "Ubuntu:26.04:LTS",
"name": "redict",
"purl": "pkg:deb/ubuntu/redict@7.3.6+ds-1?arch=source\u0026distro=resolute"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"7.3.5+ds-1",
"7.3.5+ds-1ubuntu0.1",
"7.3.6+ds-1"
]
}
],
"aliases": [],
"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": "UBUNTU-CVE-2025-21605",
"modified": "2026-10-17T09:30:28Z",
"published": "2025-04-23T16:15:00Z",
"references": [
{
"type": "REPORT",
"url": "https://ubuntu.com/security/CVE-2025-21605"
},
{
"type": "REPORT",
"url": "https://www.cve.org/CVERecord?id=CVE-2025-21605"
},
{
"type": "REPORT",
"url": "https://github.com/redis/redis/security/advisories/GHSA-r67f-p999-2gff"
},
{
"type": "REPORT",
"url": "https://github.com/valkey-io/valkey/pull/1994"
},
{
"type": "REPORT",
"url": "https://github.com/redis/redis/releases/tag/7.4.3"
}
],
"related": [],
"schema_version": "1.7.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"upstream": [
"CVE-2025-21605"
]
}
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Sightings
| Author | Source | Type | Date | Other |
|---|
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.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
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