CVE-2021-3635
A flaw was found in the Linux kernel netfilter implementation in versions prior to 5.5-rc7. A user with root (CAP_SYS_ADMIN) access is able to panic the system when issuing netfilter netflow commands.
02 Description
A flaw was found in the Linux kernel netfilter implementation in versions prior to 5.5-rc7. A user with root (CAP_SYS_ADMIN) access is able to panic the system when issuing netfilter netflow commands.
03 Exploitation and scoring
- Exploitation
- Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
- SSVC decision
- Not assessed by CISA
- EPSS probability
- 0.24% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 15.9% of scored records. A rank, not a probability.
- NVD base score
- 4.4 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
- NVD analysis status
- Modified. NVD last modified this record on 2026-06-17.
- Red Hat severity
- Low. 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
- 2021-08-13 13:22Z5 YR AGO
- Last updated
- 2024-08-03 17:01Z2 YR AGO
- Reserved
- 2021-07-02
- Assigning CNA
- redhat
- Record state
- PUBLISHED
- Severity
- Not rated by the issuing CNA
- CNA CVSS vector
- Not published by the issuing CNA
- Weaknesses
- CWE-119Improper Restriction of Operations within the Bounds of a Memory BufferClass
- Data version
- 5.1
- Document digest
- a45ebc59cd9cba47a3f1f99d40b69fce464c47b4b916191f9e8cd944431a5ccb
05 Affected products
06 References
- bugzilla.redhat.comhttps://bugzilla.redhat.com/show_bug.cgi?id=1976946
07 Fixed in
AlmaLinux 8
- kernel-tools-libs-devel Fixed in 4.18.0-348.el8
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 8
- kernel-tools-libs-devel Fixed in 4.18.0-348.el8
Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
Debian 12
- linux Fixed in 5.4.19-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- linux Fixed in 5.4.19-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- linux Fixed in 5.4.19-1
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-aws-5.0 No fix yet
- linux-aws-5.3 No fix yet
- linux-azure No fix yet
- linux-azure-5.3 No fix yet
- linux-azure-edge No fix yet
- linux-gcp No fix yet
- linux-gcp-5.3 No fix yet
- linux-gcp-edge No fix yet
- linux-gke-4.15 No fix yet
- linux-hwe No fix yet
- linux-hwe-edge No fix yet
- linux-oem No fix yet
- linux-oem-osp1 Fixed in 5.0.0-1043.48
- linux-oracle-5.0 No fix yet
- linux-oracle-5.3 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 20.04 LTS
- linux-aws-5.8 No fix yet
- linux-gcp-5.8 No fix yet
- linux-oem-5.6 No fix yet
- linux-oracle-5.8 No fix yet
- linux-raspi2 No fix yet
- linux-riscv No fix yet
- 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.
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.