CVE-2020-8631: canonical cloud-init Use of Insufficiently Random Values
CVSS: 5.5v3.1MediumModified
AliasesUBUNTU-CVE-2020-8631DEBIAN-CVE-2020-8631
Published 05-02-2020Last modified 04-08-2024
Vulnerability summary
CVE-2020-8631 is a medium (CVSS 5.5) Use of Insufficiently Random Values vulnerability in canonical cloud-init. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 36.3% of scored vulnerabilities.
CVSS score
5.5/10
010
Medium · v3.1 (NVD)EPSS score
0.43%
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 9 · Related 5Timeline
- 05-02-2020PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
Description
cloud-init through 19.4 relies on Mersenne Twister for a random password, which makes it easier for attackers to predict passwords, because rand_str in cloudinit/util.py calls the random.choice function.
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
0.43%
Chance of exploitation in the next 30 days
Percentile
36%
Versus all other CVEs
30-day change
0.00 pp
From 0.43% on 19-09-2026
19-09-202619-10-2026
EPSS score0.43%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Debian2 products
- cloud-init< 19.4-2
- debian_linuxEOL8.0
Canonical1 product
- cloud-init≤ 19.4
Opensuse1 product
- leapEOL15.1
Ubuntu1 product
- cloud-initAll versions (No fix recorded) | < 20.2-45-g5f7825e2-0ubuntu1~18.04.1
4 vendors · 5 products
References
8 links- bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/1860795X Refsource MISCIssue TrackingPatchThird Party Advisory
lists.debian.org/debian-lts-announce/2020/02/msg00021.htmlMailing ListX Refsource MLISTThird Party Advisory- lists.opensuse.org/opensuse-security-announce/2020-03/msg00042.htmlVendor AdvisoryX Refsource SUSEMailing ListThird Party Advisory
