CVE-2021-32626: debian debian_linux Heap-based Buffer Overflow
Vulnerability summary
CVE-2021-32626 is a high (CVSS 8.8) Heap-based Buffer Overflow vulnerability in debian debian_linux. EPSS estimates a 16.21% chance of exploitation in the next 30 days, higher than 96.9% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 14 · Related 4Timeline
- 04-10-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
Description
Redis is an open source, in-memory database that persists on disk. In affected versions specially crafted Lua scripts executing in Redis can cause the heap-based Lua stack to be overflowed, due to incomplete checks for this condition. This can result with heap corruption and potentially remote code execution. This problem exists in all versions of Redis with Lua scripting support, starting from 2.6. The problem is fixed in versions 6.2.6, 6.0.16 and 5.0.14. For users unable to update an additional workaround to mitigate the problem without patching the redis-server executable is to prevent users from executing Lua scripts. This can be done using ACL to restrict EVAL and EVALSHA commands.
CVSS metrics
6 scores · 5 sources · 2 versions- CVE.orgCNA7.5HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HDiffers
- OSV · AlpineEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · UbuntuEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
16.21%
Chance of exploitation in the next 30 days
Percentile
97%
Versus all other CVEs
30-day change
0.00 pp
From 16.21% 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-122Heap-based Buffer OverflowA heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
- CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.
Affected systems
Debian2 products
- redis< 5:6.0.16-1
- debian_linuxEOL10.0 | 11.0
Netapp2 products
Alpine1 product
- redis≥ 2.6, < 5.0.14-r0 | ≥ 2.6, < 6.0.16-r0 | ≥ 2.6, < 6.2.6-r0
Fedoraproject1 product
- fedoraEOL33 | 34 | 35
Oracle1 product
- communications_operations_monitor4.3 | 4.4 | 5.0
Redis1 product
- redis≥ 2.6.0, < 5.0.14 | ≥ 2.6, < 5.0.14 | ≥ 6.0.0, < 6.0.16 | ≥ 6.2.0, < 6.2.6
Ubuntu1 product
- redis< 2:2.8.4-2ubuntu0.2+esm2 | < 2:3.0.6-1ubuntu0.4+esm1 | < 5:4.0.9-1ubuntu0.2+esm3 | < 5:5.0.7-2ubuntu0.1+esm1
7 vendors · 9 products
References
16 links- github.com/redis/redis/security/advisories/GHSA-p486-xggp-782cX Refsource CONFIRMREPORTThird Party Advisory
- github.com/redis/redis/commit/666ed7facf4524bf6d19b11b20faa2cf93fdf591X Refsource MISCREPORTPatchThird Party Advisory
