CVE-2021-26313: amd all supported processors Observable Timing Discrepancy
CVSS: 5.5v3.1MediumModified
AliasesUBUNTU-CVE-2021-26313DEBIAN-CVE-2021-26313
Published 09-06-2021Last modified 16-09-2024
Vulnerability summary
CVE-2021-26313 is a medium (CVSS 5.5) Observable Timing Discrepancy vulnerability in amd all supported processors. EPSS estimates a 0.33% chance of exploitation in the next 30 days, higher than 24.4% of scored vulnerabilities.
CVSS score
5.5/10
010
Medium · v3.1 (NVD)EPSS score
0.33%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 1Timeline
- 09-06-2021PublishedVulnerability first disclosed.
- 16-09-2024Last modifiedVulnerability information updated.
Description
Potential speculative code store bypass in all supported CPU products, in conjunction with software vulnerabilities relating to speculative execution of overwritten instructions, may cause an incorrect speculation and could result in data leakage.
CVSS metrics
4 scores · 3 sources · 2 versionsMedium 5.5Preferred score · NVD (NIST)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:NSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Low 2.1Preferred score · NVD (NIST)
AV:L/AC:L/Au:N/C:P/I:N/A:NSourcesSingle source
EPSS trend
Probability
0.33%
Chance of exploitation in the next 30 days
Percentile
24%
Versus all other CVEs
30-day change
0.00 pp
From 0.33% on 19-09-2026
19-09-202619-10-2026
EPSS score0.33%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-208Observable Timing DiscrepancyTwo separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.
- CWE-203Observable DiscrepancyThe product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor.
Affected systems
Intel4 products
Debian2 products
- xen< 4.14.2+25-gb6a8c4f72d-1
- debian_linuxEOL10.0
Amd1 product
- all supported processors≥ unspecified, < undefined
Arm1 product
Broadcom1 product
- bcm2711na
Ubuntu1 product
- xenAll versions (No fix recorded)
6 vendors · 10 products
