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CVE-2021-32675

HIGHCVSS 7.5/10EPSS 15.78%

Last modified

CVE-2021-32675 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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). EPSS estimates a 15.78% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
7.5/10

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

EPSS Probability
15.78%

96.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
RedisRedis>= 5.0.0, < 5.0.14
RedisRedis>= 6.0.0, < 6.0.16
RedisRedis>= 6.2.0, < 6.2.6
FedoraprojectFedora33
FedoraprojectFedora34
FedoraprojectFedora35
DebianDebian Linux10.0
DebianDebian Linux11.0
NetappManagement Services For Element SoftwareAll versions
NetappManagement Services For Netapp HciAll versions
OracleCommunications Operations Monitor4.3
OracleCommunications Operations Monitor4.4
OracleCommunications Operations Monitor5.0

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2021-32675?
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.
How severe is CVE-2021-32675?
CVE-2021-32675 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 15.78% probability of exploitation in the next 30 days.
How do I fix CVE-2021-32675?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-32675?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST