CVE-2021-32687: Integer overflow issue with intsets in Redis
An integer overflow issue was found in redis. The vulnerability involves changing the default "set-max-intset-entries" configuration parameter to a very large value and constructing specially crafted commands to manipulate sets. This flaw allows a remote attacker to leak arbitrary contents of the heap or 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. An integer overflow bug affecting all versions of Redis can be exploited to corrupt the heap and potentially be used to leak arbitrary contents of the heap or trigger remote code execution. The vulnerability involves changing the default set-max-intset-entries configuration parameter to a very large value and constructing specially crafted commands to manipulate sets. The problem is fixed in Redis versions 6.2.6, 6.0.16 and 5.0.14. An additional workaround to mitigate the problem without patching the redis-server executable is to prevent users from modifying the set-max-intset-entries 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 prevent unprivileged users from using the CONFIG SET command, which prevents modifying the set-max-intset-entries configuration parameter.
Redis ACL configuration (disallow CONFIG SET) = disallow
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is CVE-2021-32687?
CVE-2021-32687 is an integer overflow issue found in Redis, an open-source in-memory database, that can potentially lead to heap corruption and remote code execution.
How does CVE-2021-32687 affect Redis?
CVE-2021-32687 affects all versions of Redis.
What is the severity of CVE-2021-32687?
The severity of CVE-2021-32687 is high, with a CVSS score of 7.5.
How can CVE-2021-32687 be exploited?
CVE-2021-32687 can be exploited by changing the default set-max-intset-entries configuration.
How do I fix CVE-2021-32687?
To fix CVE-2021-32687, it is recommended to update Redis to version 6.2.6 or apply the appropriate patches provided by the vendor.