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RedisDatabase / datastore

CVE-2021-32627

HIGH · 7.5 CVSS v3.1 Published 2021-10-04
Fix available
A fix is available. Upgrade to 5.0.14 / 6.0.16 or later.
See remediation →
81/100
Remediation priority · High
Remotely reachable Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Redis is an open source, in-memory database that persists on disk. In affected versions an integer overflow bug in Redis can be exploited to corrupt the heap and potentially result with remote code execution. The vulnerability involves changing the default proto-max-bulk-len and client-query-buffer-limit configuration parameters to very large values and constructing specially crafted very large stream elements. The problem is fixed in Redis 6.2.6, 6.0.16 and 5.0.14. For users unable to upgrade an additional workaround to mitigate the problem without patching the redis-server executable is to prevent users from modifying the proto-max-bulk-len configuration parameter. This can be done using ACL to restrict unprivileged users from using the CONFIG SET command.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-190

An arithmetic operation produces a value too large for its type and wraps around to an unexpected — often tiny or negative — number. That miscalculated value then drives a memory allocation or a bounds check, opening the door to corruption. The fix is checked arithmetic and validating sizes before they're used.

General guidance for the integer overflow class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
RedisDatabase / datastore
Affected:>= 5.0.0, < 5.0.14>= 6.0.0, < 6.0.16>= 6.2.0, < 6.2.6
FedoraOperating system
Affected:= 33= 34= 35
Debian LinuxOperating system
Affected:= 10.0= 11.0
Management Services For Element SoftwareApplication
Affected:all versions
Management Services For Netapp HciApplication
Affected:all versions
Communications Operations MonitorApplication
Affected:= 4.3= 4.4= 5.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
High
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 5.0.14 / 6.0.16 / 6.2.6 or later
Fixed in 5.0.146.0.166.2.6
Vendor patch github.com →
Recommended fix High confidence

Redis 5.0.14, 6.0.16, or 6.2.6 (depending on your current major version)

  1. Upgrade Redis to version 5.0.14, 6.0.16, or 6.2.6 (or later) to resolve the integer overflow vulnerability
  2. If upgrading is not immediately possible, implement an ACL rule to prevent unprivileged users from using the CONFIG SET command: ACL SETUSER <username> +@all -CONFIG
  3. Alternatively, specifically restrict the proto-max-bulk-len and client-query-buffer-limit configuration parameters from being modified by unprivileged users
  4. After applying the fix or workaround, verify the Redis service is running correctly and test that legitimate workloads function as expected
Caveat Minor version upgrades within the same major version (e.g., 6.0.x to 6.0.16) typically have low risk; however, always review release notes for any backward-incompatible changes before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $3,200. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-32627 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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