CVE-2020-27170: canonical ubuntu_linux Observable Discrepancy
Vulnerability summary
CVE-2020-27170 is a medium (CVSS 4.7) Observable Discrepancy vulnerability in canonical ubuntu_linux. EPSS estimates a 0.56% chance of exploitation in the next 30 days, higher than 46.9% of scored vulnerabilities.
Not severe (CVSS 4.7, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 23 · Related 18Timeline
- 20-03-2021PublishedVulnerability first disclosed.
- 08-10-2026Last modifiedVulnerability information updated.
Description
An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c performs undesirable out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory, aka CID-f232326f6966. This affects pointer types that do not define a ptr_limit.
CVSS metrics
4 scores · 3 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated4.7MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
- OSV · DebianEcosystem advisory · calculated4.7MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
0.56%
Chance of exploitation in the next 30 days
Percentile
47%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.56% 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.
Ubuntu50 products
- linuxAll versions (No fix recorded) | < 4.15.0-140.144 | < 5.4.0-70.78
- linux-awsAll versions (No fix recorded) | < 4.15.0-1097.104 | < 5.4.0-1041.43
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.3All versions (No fix recorded)
- linux-aws-5.4< 5.4.0-1041.43~18.04.1
Debian2 products
- linux< 5.10.24-1
- debian_linuxEOL9.0
Canonical1 product
- ubuntu_linuxEOL14.04 | 16.04 | 18.04 | 20.04
Fedoraproject1 product
- fedoraEOL32 | 33 | 34
Linux1 product
- linux_kernel< 5.11.8
5 vendors · 55 products
References
15 links- www.openwall.com/lists/oss-security/2021/03/19/2X Refsource MISCREPORTMailing ListPatchThird Party Advisory
lists.debian.org/debian-lts-announce/2021/03/msg00035.htmlMailing ListX Refsource MLISTThird Party Advisory- packetstormsecurity.com/files/162117/Kernel-Live-Patch-Security-Notice-LSN-0075-1.htmlX Refsource MISCThird Party AdvisoryVDB Entry
