CVE-2021-31440: linux kernel Incorrect Calculation
Vulnerability summary
CVE-2021-31440 is a high (CVSS 8.8) Incorrect Calculation vulnerability in linux kernel. EPSS estimates a 1.75% chance of exploitation in the next 30 days, higher than 77.9% of scored vulnerabilities.
Not severe (CVSS 8.8, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 7 · Related 3Timeline
- 21-05-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
Description
This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel 5.11.15. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the handling of eBPF programs. The issue results from the lack of proper validation of user-supplied eBPF programs prior to executing them. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the kernel. Was ZDI-CAN-13661.
CVSS metrics
7 scores · 4 sources · 3 versions- OSV · DebianEcosystem advisory · calculated7.0HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVDNIST7.0HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · UbuntuEcosystem advisory · calculated8.8HighCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- NVDNIST8.8HighCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS trend
Probability
1.75%
Chance of exploitation in the next 30 days
Percentile
78%
Versus all other CVEs
30-day change
No change 0.00 pp
From 1.75% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu23 products
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.3All versions (No fix recorded)
- linux-aws-5.8< 5.8.0-1038.40~20.04.1
- linux-azureAll versions (No fix recorded)
- linux-azure-5.3All versions (No fix recorded)
Linux2 products
- kernel5.11.15
- linux_kernel≥ 5.7, < 5.10.37 | ≥ 5.11, < 5.11.21 | ≥ 5.12, < 5.12.4
Debian1 product
- linux< 5.10.38-1
4 vendors · 35 products
