CVE-2021-32627: Integer overflow issue with Streams in Redis
An integer overflow issue was found in redis. 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 large stream elements. This flaw allows a remote attacker to corrupt the heap and potentially trigger remote code execution. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
Other sources
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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
redhat/redisto a version that resolves this vulnerability.Fixed in 0:3.2.8-5.el7 - Upgrade
Upgrade
redhat/rh-redis5-redisto a version that resolves this vulnerability.Fixed in 0:5.0.5-3.el7 - Upgrade
Upgrade
debian/redisto a version that resolves this vulnerability.Fixed in 5:5.0.14-1+deb10u2Fixed in 5:5.0.14-1+deb10u5Fixed in 5:6.0.16-1+deb11u2Fixed in 5:7.0.11-1Fixed in 5:7.0.14-1 - Upgrade
Upgrade
redhat/redisto a version that resolves this vulnerability.Fixed in 6.2.6 - Upgrade
Upgrade
redhat/redisto a version that resolves this vulnerability.Fixed in 6.0.16 - Upgrade
Upgrade
redhat/redisto a version that resolves this vulnerability.Fixed in 5.0.14 - Upgrade
Upgrade
Redisto a version that resolves this vulnerability.Fixed in 6.2.6 - Upgrade
Upgrade
Redisto a version that resolves this vulnerability.Fixed in 6.0.16 - Upgrade
Upgrade
Redisto a version that resolves this vulnerability.Fixed in 5.0.14 - Configuration
Use Redis ACL to disallow usage of the CONFIG SET command for unprivileged users, preventing clients from changing the proto-max-bulk-len configuration parameter.
Redis ACL CONFIG SET = disallow (remove permission from unprivileged users)
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is CVE-2021-32627?
CVE-2021-32627 is an integer overflow issue found in Redis that can be exploited to corrupt the heap and potentially result in remote code execution.
How does CVE-2021-32627 affect Redis?
CVE-2021-32627 involves changing the default proto-max-bulk-len and client-query-buffer-... settings in Redis, which can lead to an integer overflow vulnerability.
How severe is CVE-2021-32627?
CVE-2021-32627 has a severity score of 7.5 (High).
Which versions of Redis are affected by CVE-2021-32627?
Redis versions up to and including 6.2.6, 6.0.16, and 5.0.14 are affected by CVE-2021-32627.
How can CVE-2021-32627 be mitigated?
To mitigate CVE-2021-32627, update Redis to version 6.2.7, 6.0.17, or 5.0.15, which contain the necessary fixes.