CVE-2022-36021 | Redis string pattern matching can be abused to achieve Denial of Service

Redis is an in-memory database that persists on disk. Authenticated users can use string matching commands (like `SCAN` or `KEYS`) with a specially crafted pattern to trigger a denial-of-service attack on Redis, causing it to hang and consume 100% CPU time. The problem is fixed in Redis versions 6.0.18, 6.2.11, 7.0.9.

Published: 2023-03-01 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-36021 is rated Moderate Risk (55.9/100): CVSS Medium severity, with high exploitation likelihood (EPSS 60.65%, 98th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2022-36021

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-16 61.17% 60.65% -0.52%
2 2026-05-03 60.65% 61.17% +0.52%
3 2026-03-17 — 60.65% —

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-36021

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]

Weakness enumeration for CVE-2022-36021

OS Trackers for CVE-2022-36021

vendor priority summary link
alpine medium CVE-2022-36021: 1 source package rows (redis); 49 state rows across 4 repos (3.19-main, 3.22-community, edge-community, edge-main); fixed 0, open 49. https://security.alpinelinux.org/vuln/CVE-2022-36021
debian not yet assigned CVE-2022-36021 not yet assigned priority: Debian including 1 source packages (redis), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2022-36021
gentoo normal CVE-2022-36021: 1 GLSA(s) (202408-05), 1 atom(s) (dev-db/redis); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2022-36021
redhat medium — https://access.redhat.com/security/cve/CVE-2022-36021
suse high CVE-2022-36021 severity important: SUSE including 7 source package names (redis-6.0.14-150200.6.20.1, redis-6.2.17-1.module+el8.10.0+22680+748527fd, …), 23 product×package rows across 20 product lines (SUSE Enterprise Storage 7, SUSE Enterprise Storage 7.1, … (20 product lines)): Fixed 23. https://www.suse.com/security/cve/CVE-2022-36021/
ubuntu medium CVE-2022-36021 medium priority: Ubuntu including 1 source packages (redis), 13 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): released 6, not-affected 5, ignored 2. https://ubuntu.com/security/CVE-2022-36021

Affected software / configurations for CVE-2022-36021

Vendor Product Version Raw CPE
redis redis < 6.0.18 cpe:2.3:a:redis:redis:*:*:*:*:*:*:*:*
redis redis >= 6.2.0, < 6.2.11 cpe:2.3:a:redis:redis:*:*:*:*:*:*:*:*
redis redis >= 7.0.0, < 7.0.9 cpe:2.3:a:redis:redis:*:*:*:*:*:*:*:*

References for CVE-2022-36021

cvelogic Threat Intelligence