CVE-2021-3655
A vulnerability was found in the Linux kernel in versions prior to v5.14-rc1. Missing size validations on inbound SCTP packets may allow the kernel to read uninitialized memory.
02 Description
A vulnerability was found in the Linux kernel in versions prior to v5.14-rc1. Missing size validations on inbound SCTP packets may allow the kernel to read uninitialized memory.
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.30% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 23.3% of scored records. A rank, not a probability.
- NVD base score
- 3.3 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- NVD analysis status
- Modified. NVD last modified this record on 2026-10-08.
- Red Hat severity
- Moderate. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2021-08-05 20:48Z5 YR AGO
- Last updated
- 2026-10-08 21:03Z20 DAYS AGO
- Reserved
- 2021-07-20
- Assigning CNA
- redhat
- Record state
- PUBLISHED
- Severity
- Not rated by the issuing CNA
- CNA CVSS vector
- Not published by the issuing CNA
- Weaknesses
- Data version
- 5.2
- Document digest
- ddfdc9b6d1d5962d5f756961bb45e8d2e6c192ddf9f646235a4699529702ed1b
05 Affected products
06 References
- bugzilla.redhat.comhttps://bugzilla.redhat.com/show_bug.cgi?id=1984024
- lists.debian.org[debian-lts-announce] 20211015 [SECURITY] [DLA 2785-1] linux-4.19 security updatehttps://lists.debian.org/debian-lts-announce/2021/10/msg00010.html
- lists.debian.org[debian-lts-announce] 20211216 [SECURITY] [DLA 2843-1] linux security updatehttps://lists.debian.org/debian-lts-announce/2021/12/msg00012.html
07 Fixed in
Arch Linux
- linux Fixed in 5.13.4.arch1-1
- linux-hardened Fixed in 5.12.18.hardened1-1
- linux-lts Fixed in 5.10.51-1
- linux-zen Fixed in 5.13.4.zen1-1
Source: Arch Linux Security Tracker, the Arch Linux security team. Reformatted by exploit.cc.
Debian 12
- linux Fixed in 5.10.46-3
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- linux Fixed in 5.10.46-3
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- linux Fixed in 5.10.46-3
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 16.04 LTS
- linux-hwe-edge No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 18.04 LTS
- linux Fixed in 4.15.0-162.170
- linux-aws Fixed in 4.15.0-1115.122
- linux-aws-5.0 No fix yet
- linux-aws-5.3 No fix yet
- linux-aws-5.4 Fixed in 5.4.0-1060.63~18.04.1
- linux-azure No fix yet
- linux-azure-4.15 Fixed in 4.15.0-1126.139
- linux-azure-5.3 No fix yet
- linux-azure-5.4 Fixed in 5.4.0-1064.67~18.04.1
- linux-azure-edge No fix yet
- linux-dell300x Fixed in 4.15.0-1030.35
- linux-gcp No fix yet
- linux-gcp-4.15 Fixed in 4.15.0-1111.125
- linux-gcp-5.3 No fix yet
- linux-gcp-5.4 Fixed in 5.4.0-1058.62~18.04.1
- linux-gcp-edge No fix yet
- linux-gke-4.15 No fix yet
- linux-gke-5.4 Fixed in 5.4.0-1056.59~18.04.1
- linux-gkeop-5.4 Fixed in 5.4.0-1027.28~18.04.1
- linux-hwe No fix yet
- linux-hwe-5.4 Fixed in 5.4.0-91.102~18.04.1
- linux-hwe-edge No fix yet
- linux-kvm Fixed in 4.15.0-1102.104
- linux-oem No fix yet
- linux-oracle Fixed in 4.15.0-1083.91
- linux-oracle-5.0 No fix yet
- linux-oracle-5.3 No fix yet
- linux-oracle-5.4 Fixed in 5.4.0-1058.62~18.04.1
- linux-raspi-5.4 Fixed in 5.4.0-1047.52~18.04.1
- linux-raspi2 Fixed in 4.15.0-1098.104
- linux-snapdragon Fixed in 4.15.0-1115.124
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 20.04 LTS
- linux Fixed in 5.4.0-91.102
- linux-aws Fixed in 5.4.0-1060.63
- linux-aws-5.11 Fixed in 5.11.0-1022.23~20.04.1
- linux-aws-5.8 No fix yet
- linux-azure Fixed in 5.4.0-1064.67
- linux-azure-5.11 Fixed in 5.11.0-1022.23~20.04.1
- linux-azure-5.8 No fix yet
- linux-bluefield Fixed in 5.4.0-1022.25
- linux-gcp Fixed in 5.4.0-1058.62
- linux-gcp-5.11 Fixed in 5.11.0-1023.25~20.04.1
- linux-gcp-5.8 No fix yet
- linux-gke Fixed in 5.4.0-1056.59
- linux-gkeop Fixed in 5.4.0-1027.28
- linux-hwe-5.11 Fixed in 5.11.0-41.45~20.04.1
- linux-hwe-5.13 Fixed in 5.13.0-22.22~20.04.1
- linux-hwe-5.8 No fix yet
- linux-ibm Fixed in 5.4.0-1008.9
- linux-intel-5.13 No fix yet
- linux-kvm Fixed in 5.4.0-1050.52
- linux-oem-5.10 Fixed in 5.10.0-1051.53
- linux-oem-5.13 Fixed in 5.13.0-1020.24
- linux-oem-5.6 No fix yet
- linux-oracle Fixed in 5.4.0-1058.62
- linux-oracle-5.11 Fixed in 5.11.0-1022.23~20.04.1
- linux-oracle-5.8 No fix yet
- linux-raspi Fixed in 5.4.0-1047.52
- linux-raspi2 No fix yet
- linux-riscv No fix yet
- linux-riscv-5.11 Fixed in 5.11.0-1023.24~20.04.1
- linux-riscv-5.8 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- linux-intel-iot-realtime No fix yet
- linux-realtime No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 24.04 LTS
- linux-raspi-realtime No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 14.04 LTS
- linux No fix yet
- linux-aws No fix yet
- linux-azure Fixed in 4.15.0-1126.139~14.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-lts-xenial No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 16.04 LTS
- linux No fix yet
- linux-aws No fix yet
- linux-aws-hwe Fixed in 4.15.0-1115.122~16.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-azure Fixed in 4.15.0-1126.139~16.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-gcp Fixed in 4.15.0-1111.125~16.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-hwe Fixed in 4.15.0-162.170~16.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-kvm No fix yet
- linux-oracle Fixed in 4.15.0-1083.91~16.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 20.04 LTS
- linux-azure-fde-5.15 Fixed in 5.15.0-1114.123~20.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS-updates 16.04 LTS
- linux-fips No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS-updates 18.04 LTS
- linux-aws-fips Fixed in 4.15.0-2056.58Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-azure-fips Fixed in 4.15.0-2038.42Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-fips Fixed in 4.15.0-1072.81Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-gcp-fips Fixed in 4.15.0-2021.23Available with Ubuntu Pro: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS-updates 20.04 LTS
- linux-aws-fips Fixed in 5.4.0-1069.73+fips2Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-azure-fips Fixed in 5.4.0-1073.76+fips1Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-fips Fixed in 5.4.0-1037.43Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-gcp-fips Fixed in 5.4.0-1067.71~20.04.1Available with Ubuntu Pro: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS 16.04 LTS
- linux-fips No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS 18.04 LTS
- linux-aws-fips No fix yet
- linux-azure-fips No fix yet
- linux-fips No fix yet
- linux-gcp-fips No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS 20.04 LTS
- linux-aws-fips No fix yet
- linux-azure-fips No fix yet
- linux-fips No fix yet
- linux-gcp-fips No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.