First published: Mon Oct 04 2021(Updated: )
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.
Credit: security-advisories@github.com
Affected Software | Affected Version | How to fix |
---|---|---|
redhat/redis | <0:3.2.8-5.el7 | 0:3.2.8-5.el7 |
redhat/rh-redis5-redis | <0:5.0.5-3.el7 | 0:5.0.5-3.el7 |
debian/redis | 5:5.0.14-1+deb10u2 5:5.0.14-1+deb10u5 5:6.0.16-1+deb11u2 5:7.0.11-1 5:7.0.14-1 | |
redhat/redis | <6.2.6 | 6.2.6 |
redhat/redis | <6.0.16 | 6.0.16 |
redhat/redis | <5.0.14 | 5.0.14 |
ioredis | >=5.0.0<5.0.14 | |
ioredis | >=6.0.0<6.0.16 | |
ioredis | >=6.2.0<6.2.6 | |
Red Hat Fedora | =33 | |
Red Hat Fedora | =34 | |
Red Hat Fedora | =35 | |
Debian Linux | =10.0 | |
Debian Linux | =11.0 | |
NetApp Management Services for Element Software | ||
NetApp Management Services for NetApp HCI | ||
Oracle Communications Operations Monitor | =4.3 | |
Oracle Communications Operations Monitor | =4.4 | |
Oracle Communications Operations Monitor | =5.0 |
Prevent unauthenticated users from connecting to Redis by using network access control tools (e.g., firewalls) or enabling TLS and requiring users to authenticate using client side certificates.
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(Appears in the following advisories)
The vulnerability ID for this flaw in Redis is CVE-2021-32675.
Redis is an open source, in-memory database that persists on disk.
The severity of CVE-2021-32675 is high with a severity value of 7.5.
CVE-2021-32675 in Redis allows an attacker to allocate arbitrary amounts of memory, potentially leading to denial of service or remote code execution.
To fix CVE-2021-32675 in Redis, upgrade to version 6.2.6, 6.0.16, or 5.0.14 depending on your current version.