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TI-2021-12343 Aliases CVE-2021-32675

DoS vulnerability in Redis

Priority MEDIUM 49CWE-770Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 9 fixed, 1 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-770.

Summary

Redis is an open source, in-memory database that persists on disk. When parsing an incoming Redis Standard Protocol (RESP) request, Redis allocates memory according to user-specified values which determine the number of elements (in the multi-bulk header) and size of each element (in the bulk header). An attacker delivering specially crafted requests over multiple connections can cause the server to allocate significant amount of memory. Because the same parsing mechanism is used to handle authentication requests, this vulnerability can also be exploited by unauthenticated users. The problem is fixed in Redis versions 6.2.6, 6.0.16 and 5.0.14. 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: Using network access control tools like firewalls, iptables, security groups, etc. or Enabling TLS and requiring users to authenticate using client side certificates.

Why it matters now

EPSS 0.16066 96th percentileScored 2026-11-07
Fix Partial redis (redis): 5.0.14, 6.0.16, 6.2.6Red Hat: 10 advisoriesRed Hat: 9 fixed, 1 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
Redisredisbefore 5.0.14; 6.0.0 to before 6.0.16; 6.2.0 to before 6.2.65.0.14, 6.0.16, 6.2.6Patch availableCNA
  • redis VendorRedis Affected before 5.0.14; 6.0.0 to before 6.0.16; 6.2.0 to before 6.2.6 Fixed in 5.0.14, 6.0.16, 6.2.6 Patch available CNA

CPE configurations NVD · 11

CPEVersionsRoleVendor
cpe:2.3:a:redis:redis:*:*:*:*:*:*:*:*5.0.0 to before 5.0.14; 6.0.0 to before 6.0.16; 6.2.0 to before 6.2.6VulnerableRedis
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*33VulnerableFedoraproject
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*34VulnerableFedoraproject
cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*35VulnerableFedoraproject
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*10.0VulnerableDebian
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*11.0VulnerableDebian
cpe:2.3:a:netapp:management_services_for_element_software:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
cpe:2.3:a:netapp:management_services_for_netapp_hci:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
cpe:2.3:a:oracle:communications_operations_monitor:4.3:*:*:*:*:*:*:*4.3VulnerableOracle
cpe:2.3:a:oracle:communications_operations_monitor:4.4:*:*:*:*:*:*:*4.4VulnerableOracle
  • cpe:2.3:a:redis:redis:*:*:*:*:*:*:*:* Versions 5.0.0 to before 5.0.14; 6.0.0 to before 6.0.16; 6.2.0 to before 6.2.6 Vulnerable ·Redis
  • cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* Versions 33 Vulnerable ·Fedoraproject
  • cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject
  • cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* Versions 35 Vulnerable ·Fedoraproject
  • cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
  • cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian
  • cpe:2.3:a:netapp:management_services_for_element_software:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
  • cpe:2.3:a:netapp:management_services_for_netapp_hci:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
  • cpe:2.3:a:oracle:communications_operations_monitor:4.3:*:*:*:*:*:*:* Versions 4.3 Vulnerable ·Oracle
  • cpe:2.3:a:oracle:communications_operations_monitor:4.4:*:*:*:*:*:*:* Versions 4.4 Vulnerable ·Oracle
Show 1 more CPE
CPEVersionsRoleVendor
cpe:2.3:a:oracle:communications_operations_monitor:5.0:*:*:*:*:*:*:*5.0VulnerableOracle
  • cpe:2.3:a:oracle:communications_operations_monitor:5.0:*:*:*:*:*:*:* Versions 5.0 Vulnerable ·Oracle

Remediation

  • Fix · CNA redis (redis) Fixed in 5.0.14, 6.0.16, 6.2.6

Red Hat 10 advisories

  • RHSA-2021:4618 Released 2021-11-11 · Red Hat rating Important
    Red Hat Advanced Cluster Management 2.4 images and security updates
    • Red Hat Advanced Cluster Management for Kubernetes 2.4 for RHEL 8 rhacm2/acm-grafana-rhel8, rhacm2/acm-must-gather-rhel8, rhacm2/acm-operator-bundle +47
  • RHSA-2021:3980 Released 2021-10-25 · Red Hat rating Important
    Red Hat OpenStack Platform 13.0 (redis) security update
    • Red Hat OpenStack Platform 13.0 - ELS redis-3.2.8-5.el7ost
    • Red Hat OpenStack Platform 13.0 for RHEL 7.6 EUS Server redis-3.2.8-5.el7ost
  • RHSA-2021:3971 Released 2021-10-25 · Red Hat rating Important
    Red Hat OpenStack Platform 10.0 (redis) security update
    • Red Hat OpenStack Platform 10.0 redis-3.2.8-5.el7ost
Show 7 more Red Hat advisories
  • RHSA-2021:3949 Released 2021-10-20 · Red Hat rating Important
    Red Hat Advanced Cluster Management 2.1.12 security fixes and container updates
    • Red Hat Advanced Cluster Management for Kubernetes 2.1 for RHEL 8 rhacm2/acm-must-gather-rhel8
  • RHSA-2021:3945 Released 2021-10-20 · Red Hat rating Important
    redis:6 security update
    • Red Hat Enterprise Linux AppStream (v. 8) redis-6.0.9-5.module+el8.4.0+12929+1bb0d2aa.aarch64::redis:6, redis-6.0.9-5.module+el8.4.0+12929+1bb0d2aa.ppc64le::redis:6, redis-6.0.9-5.module+el8.4.0+12929+1bb0d2aa.s390x::redis:6 +7
  • RHSA-2021:3946 Released 2021-10-20 · Red Hat rating Important
    redis:5 security update
    • Red Hat Enterprise Linux AppStream EUS (v. 8.1) redis-5.0.3-5.module+el8.1.0+12925+6460abef.aarch64::redis:5, redis-5.0.3-5.module+el8.1.0+12925+6460abef.ppc64le::redis:5, redis-5.0.3-5.module+el8.1.0+12925+6460abef.s390x::redis:5 +7
  • RHSA-2021:3944 Released 2021-10-20 · Red Hat rating Important
    redis:5 security update
    • Red Hat Enterprise Linux AppStream EUS (v. 8.2) redis-5.0.3-5.module+el8.2.0+12926+485b5fc9.aarch64::redis:5, redis-5.0.3-5.module+el8.2.0+12926+485b5fc9.ppc64le::redis:5, redis-5.0.3-5.module+el8.2.0+12926+485b5fc9.s390x::redis:5 +7
  • RHSA-2021:3947 Released 2021-10-20 · Red Hat rating Important
    rh-redis5-redis security update
    • Red Hat Software Collections for Red Hat Enterprise Linux Server (v. 7) rh-redis5-redis-5.0.5-3.el7
    • Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 7.7) rh-redis5-redis-5.0.5-3.el7
    • Red Hat Software Collections for Red Hat Enterprise Linux Workstation (v. 7) rh-redis5-redis-5.0.5-3.el7
  • RHSA-2021:3918 Released 2021-10-19 · Red Hat rating Important
    redis:5 security update
    • Red Hat Enterprise Linux AppStream (v. 8) redis-5.0.3-5.module+el8.4.0+12927+b9845322.aarch64::redis:5, redis-5.0.3-5.module+el8.4.0+12927+b9845322.ppc64le::redis:5, redis-5.0.3-5.module+el8.4.0+12927+b9845322.s390x::redis:5 +7
  • RHSA-2021:3873 Released 2021-10-14 · Red Hat rating Important
    Red Hat Advanced Cluster Management 2.2.9 security, bug, and container updates
    • Red Hat Advanced Cluster Management for Kubernetes 2.2 for RHEL 7 rhacm2/management-ingress-rhel7, rhacm2/memcached-exporter-rhel7, rhacm2/search-aggregator-rhel7 +1
    • Red Hat Advanced Cluster Management for Kubernetes 2.2 for RHEL 8 rhacm2/acm-must-gather-rhel8, rhacm2/acm-operator-bundle, rhacm2/acmesolver-rhel8 +47

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    redis — FEDORA-2021-61c487f241

    8 records Highest priority Priority MEDIUM 6 MEDIUM, 2 LOW

    Other records, highest priority first

    • TI-2021-12295 Lua scripts can overflow the heap-based Lua stack in RedisPriority MEDIUM 55
    • TI-2021-12297 Vulnerability in handling large ziplistsPriority MEDIUM 48
    • TI-2021-12429 Integer overflow that can lead to heap overflow in redis-cli, redis-sentinel on some platformsPriority MEDIUM 43
    Show all 8 records → Advisory →
  • Advisory ·

    redis — FEDORA-2021-8913c7900c

    8 records Highest priority Priority MEDIUM 6 MEDIUM, 2 LOW

    Other records, highest priority first

    • TI-2021-12295 Lua scripts can overflow the heap-based Lua stack in RedisPriority MEDIUM 55
    • TI-2021-12297 Vulnerability in handling large ziplistsPriority MEDIUM 48
    • TI-2021-12429 Integer overflow that can lead to heap overflow in redis-cli, redis-sentinel on some platformsPriority MEDIUM 43
    Show all 8 records → Advisory →
Show 1 more group
  • Advisory ·

    redis — FEDORA-2021-aa94492a09

    8 records Highest priority Priority MEDIUM 6 MEDIUM, 2 LOW

    Other records, highest priority first

    • TI-2021-12295 Lua scripts can overflow the heap-based Lua stack in RedisPriority MEDIUM 55
    • TI-2021-12297 Vulnerability in handling large ziplistsPriority MEDIUM 48
    • TI-2021-12429 Integer overflow that can lead to heap overflow in redis-cli, redis-sentinel on some platformsPriority MEDIUM 43
    Show all 8 records → Advisory →

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Advanced Cluster Management for Kubernetes 2AffectedNo fix yet
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2021:3918, RHSA-2021:3945
Red Hat Enterprise Linux AppStream EUS (v. 8.1)Fixed RHSA-2021:3946
Red Hat Enterprise Linux AppStream EUS (v. 8.2)Fixed RHSA-2021:3944
Red Hat OpenStack Platform 10.0Fixed RHSA-2021:3971
Red Hat OpenStack Platform 13.0 - ELSFixed RHSA-2021:3980
Red Hat OpenStack Platform 13.0 for RHEL 7.6 EUS ServerFixed RHSA-2021:3980
Red Hat Software Collections for Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2021:3947
Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 7.7)Fixed RHSA-2021:3947
Red Hat Software Collections for Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2021:3947
Not affected: 5 products
  • Red Hat 3scale API Management Platform 2
  • Red Hat Ansible Automation Platform 1.2
  • Red Hat Ansible Tower 3
  • Red Hat Enterprise Linux 9
  • Red Hat Software Collections

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-32675
  2. 2026-11-07 Fix available: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux AppStream EUS (v. 8.1), Red Hat Enterprise Linux AppStream EUS (v. 8.2) +6 · Red Hat
  3. 2026-11-07 CVSS score added · Red Hat

References

Patch 2

Advisory 7

Other 1

  • TI-2022-00463 Missing authorization in Debian redis KEVCVSS 3.1CRITICAL 10.0
  • TI-2025-31759 Redis Lua Use-After-Free may lead to remote code execution CVSS 3.1CRITICAL 10.0
  • TI-2023-18618 Heap overflow in COMMAND GETKEYS and ACL evaluation in Redis CVSS 3.1HIGH 8.8
  • TI-2024-20813 Lua library commands may lead to stack overflow and RCE in Redis CVSS 3.1HIGH 8.8
  • TI-2022-08647 Heap overflow issue with the Lua cjson library used by Redis CVSS 3.1HIGH 8.8
  • TI-2022-08549 Lua scripts can be manipulated to overcome ACL rules in Redis CVSS 3.1HIGH 7.8
See all 45 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences