Vulnerability · Published Feb 16, 2022 · Assigned by redhat
CVE-2021-3773
Critical 9.8
In plain English
A critical-severity information exposure in kernel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 5.3% (higher than 93% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)9.8Critical
Exploit odds (30 days)5.3%top 7.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack tooling1Public PoC
Official description
A flaw in netfilter could allow a network-connected attacker to infer openvpn connection endpoint information for further use in traditional network attacks.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | bpftool | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-abi-stablelists | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-core | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-cross-headers | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug-core | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug-devel | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug-modules | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug-modules-extra | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-devel | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-doc | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-headers | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-modules | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-modules-extra | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-tools | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-tools-libs | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-tools-libs-devel | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | perf | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | python3-perf | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| Rocky Linux:8 | kernel | 0:4.18.0-372.9.1.el8 | RLSA-2022:1988 |
| Rocky Linux:8 | kernel-rt | 0:4.18.0-372.9.1.rt7.166.el8 | RLSA-2022:1975 |
| Ubuntu:22.04:LTS | linux | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:25.10 | linux | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-allwinner-5.19 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-aws | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-aws | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:25.10 | linux-aws | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-aws-5.19 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-aws-6.14 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-aws-6.17 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-aws-6.2 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-aws-6.5 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-aws-6.8 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-azure | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-azure | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:25.10 | linux-azure | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-azure-5.19 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-azure-6.11 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-azure-6.14 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-azure-6.17 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-azure-6.2 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-azure-6.5 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-azure-6.8 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-azure-fde | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-azure-fde | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:25.10 | linux-azure-fde | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-azure-fde-5.19 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-azure-fde-6.14 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-azure-fde-6.17 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-azure-fde-6.2 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-azure-fde-6.8 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-azure-nvidia | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-azure-nvidia-6.14 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-gcp | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-gcp | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:25.10 | linux-gcp | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-gcp-5.19 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-gcp-6.11 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-gcp-6.14 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-gcp-6.17 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-gcp-6.2 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-gcp-6.5 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-gcp-6.8 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-gke | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-gke | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-gkeop | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-gkeop | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-hwe-5.19 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-hwe-6.11 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-hwe-6.14 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-hwe-6.17 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-hwe-6.2 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-hwe-6.5 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-hwe-6.8 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-ibm | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-ibm | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-ibm-6.8 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-intel | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-intel-iot-realtime | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-intel-iotg | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-kvm | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-lowlatency | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-lowlatency | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-5.19 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-lowlatency-hwe-6.11 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.2 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.5 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.8 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-nvidia | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-nvidia | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-nvidia-6.11 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-nvidia-6.2 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-nvidia-6.5 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-nvidia-6.8 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-nvidia-lowlatency | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-nvidia-tegra | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-nvidia-tegra | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-nvidia-tegra-igx | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-oem-5.17 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-oem-6.0 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-oem-6.1 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-oem-6.11 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-oem-6.14 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-oem-6.17 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-oem-6.5 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-oem-6.8 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-oracle | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-oracle | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:25.10 | linux-oracle | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-oracle-6.14 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-oracle-6.17 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-oracle-6.5 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-oracle-6.8 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-raspi | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-raspi | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:25.10 | linux-raspi | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-raspi-realtime | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:25.10 | linux-realtime | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-riscv | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-riscv | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:25.10 | linux-riscv | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-riscv-5.19 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-riscv-6.14 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-riscv-6.17 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-riscv-6.5 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-riscv-6.8 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-starfive-5.19 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-starfive-6.2 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-starfive-6.5 | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:24.04:LTS | linux-xilinx | no fix listed | UBUNTU-CVE-2021-3773 |
| Ubuntu:22.04:LTS | linux-xilinx-zynqmp | no fix listed | UBUNTU-CVE-2021-3773 |
Affected products (as reported)
Weakness: CWE-200