CVE-2021-32761: debian debian_linux Out-of-bounds Read
Vulnerability summary
CVE-2021-32761 is a high (CVSS 7.5) Out-of-bounds Read vulnerability in debian debian_linux. EPSS estimates a 36.55% chance of exploitation in the next 30 days, higher than 98.4% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 3 · Related 2Timeline
- 21-07-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
6 scores · 5 sources · 2 versions- OSV · AlpineEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
36.55%
Chance of exploitation in the next 30 days
Percentile
98%
Versus all other CVEs
30-day change
-1.08 pp
From 37.63% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-125Out-of-bounds ReadThe product reads data past the end, or before the beginning, of the intended buffer.
- CWE-680Integer Overflow to Buffer OverflowThe product performs a calculation to determine how much memory to allocate, but an integer overflow can occur that causes less memory to be allocated than expected, leading to a buffer overflow.
- CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
Affected systems
Debian2 products
- redis< 5:6.0.15-1 | < 3:3.2.6-3+deb9u5 | < 3:3.2.6-3+deb9u6
- debian_linuxEOL9.0 | 10.0 | 11.0
Alpine1 product
- redis≥ 2.2.0, < 5.0.13-r0 | ≥ 2.2.0, < 6.0.13-r0 | ≥ 2.2.0, < 6.2.5-r0
Fedoraproject1 product
- fedoraEOL33 | 34
Redis1 product
- redis≥ 2.2, < 5.0.13 | ≥ 6.0.0, < 6.0.15 | ≥ 6.2.0, < 6.2.5
Redislabs1 product
- redis≥ 2.2.0, < 5.0.13 | ≥ 6.0, < 6.0.15 | ≥ 6.2.0, < 6.2.5
Ubuntu1 product
- redis< 2:2.8.4-2ubuntu0.2+esm2 | < 2:3.0.6-1ubuntu0.4+esm1 | < 5:4.0.9-1ubuntu0.2+esm3
6 vendors · 7 products
References
14 links- github.com/redis/redis/security/advisories/GHSA-8wxq-j7rp-g8wjX Refsource CONFIRMREPORTThird Party Advisory
- lists.debian.org/debian-lts-announce/2021/07/msg00017.htmlMailing ListX Refsource MLISTThird Party Advisory
- lists.debian.org/debian-lts-announce/2021/08/msg00026.htmlMailing ListX Refsource MLISTThird Party Advisory