{"id":"UBUNTU-CVE-2021-32761","details":"Redis is an in-memory database that persists on disk. A vulnerability involving out-of-bounds read and integer overflow to buffer overflow exists starting with version 2.2 and prior to versions 5.0.13, 6.0.15, and 6.2.5. On 32-bit systems, Redis `*BIT*` command are vulnerable to integer overflow that can potentially be exploited to corrupt the heap, leak arbitrary heap contents or trigger remote code execution. The vulnerability involves changing the default `proto-max-bulk-len` configuration parameter to a very large value and constructing specially crafted commands bit commands. This problem only affects Redis on 32-bit platforms, or compiled as a 32-bit binary. Redis versions 5.0.`3m 6.0.15, and 6.2.5 contain patches for this issue. 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.","modified":"2026-01-30T01:40:15.913435Z","published":"2021-07-21T21:15:00Z","related":["USN-5221-1"],"upstream":["CVE-2021-32761"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-32761"},{"type":"REPORT","url":"https://github.com/redis/redis/security/advisories/GHSA-8wxq-j7rp-g8wj"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5221-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-32761"}],"affected":[{"package":{"name":"redis","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/redis@2:2.8.4-2ubuntu0.2+esm2?arch=source&distro=trusty/esm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2:2.8.4-2ubuntu0.2+esm2"}]}],"versions":["2:2.6.13-1","2:2.6.16-3","2:2.8.0-1","2:2.8.2-1","2:2.8.4-2","2:2.8.4-2ubuntu0.2","2:2.8.4-2ubuntu0.2+esm1"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_name":"redis-server","binary_version":"2:2.8.4-2ubuntu0.2+esm2"},{"binary_name":"redis-tools","binary_version":"2:2.8.4-2ubuntu0.2+esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-32761.json"}},{"package":{"name":"redis","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/redis@2:3.0.6-1ubuntu0.4+esm1?arch=source&distro=esm-apps/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2:3.0.6-1ubuntu0.4+esm1"}]}],"versions":["2:3.0.3-3","2:3.0.5-1","2:3.0.5-2","2:3.0.5-3","2:3.0.5-4","2:3.0.6-1","2:3.0.6-1ubuntu0.2","2:3.0.6-1ubuntu0.3","2:3.0.6-1ubuntu0.4"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro","binaries":[{"binary_name":"redis-sentinel","binary_version":"2:3.0.6-1ubuntu0.4+esm1"},{"binary_name":"redis-server","binary_version":"2:3.0.6-1ubuntu0.4+esm1"},{"binary_version":"2:3.0.6-1ubuntu0.4+esm1","binary_name":"redis-tools"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-32761.json"}},{"package":{"name":"redis","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/redis@5:4.0.9-1ubuntu0.2+esm3?arch=source&distro=esm-apps/bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5:4.0.9-1ubuntu0.2+esm3"}]}],"versions":["4:4.0.1-7","4:4.0.2-6","4:4.0.2-9","5:4.0.5-1","5:4.0.6-1","5:4.0.6-2","5:4.0.7-1","5:4.0.8-1","5:4.0.8-2","5:4.0.9-1","5:4.0.9-1ubuntu0.1","5:4.0.9-1ubuntu0.2","5:4.0.9-1ubuntu0.2+esm2"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro","binaries":[{"binary_name":"redis","binary_version":"5:4.0.9-1ubuntu0.2+esm3"},{"binary_name":"redis-sentinel","binary_version":"5:4.0.9-1ubuntu0.2+esm3"},{"binary_name":"redis-server","binary_version":"5:4.0.9-1ubuntu0.2+esm3"},{"binary_name":"redis-tools","binary_version":"5:4.0.9-1ubuntu0.2+esm3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-32761.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"},{"type":"Ubuntu","score":"medium"}]}