CVSS 3.1
7.4 highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NCVE-2021-20322
High (7.4). EPSS 6.9% chance of exploitation in the next 30 days.
A flaw in the processing of received ICMP errors (ICMP fragment needed and ICMP redirect) in the Linux kernel functionality was found to allow the ability to quickly scan open UDP ports. This flaw allows an off-path remote user to effectively bypass the source port UDP randomization. The highest threat from this vulnerability is to confidentiality and possibly integrity, because software that relies on UDP source port randomization are indirectly affected as well.
Severity
- EPSS
- 6.9% chance of exploitation in the next 30 days; higher than 94% of CVEs (scores of 2026-10-31)
- CWE
- CWE-330
- Published
- Modified
- Record from
- the NVD, synced
Affected
- debian:debian_linux
- fedoraproject:fedora
- linux:linux_kernel
- netapp:active_iq_unified_manager
- netapp:aff_a700s_firmware
- netapp:aff_baseboard_management_controller_firmware
- netapp:e-series_santricity_os_controller
- netapp:fas_baseboard_management_controller_firmware
- netapp:h300e_firmware
- netapp:h300s_firmware
- netapp:h410s_firmware
- netapp:h500e_firmware
- netapp:h500s_firmware
- netapp:h700e_firmware
- netapp:h700s_firmware
- netapp:hci_compute_node_firmware
- netapp:solidfire\,_enterprise_sds_\&_hci_storage_node
- netapp:solidfire_\&_hci_management_node
- oracle:communications_cloud_native_core_binding_support_function
- oracle:communications_cloud_native_core_network_exposure_function
- oracle:communications_cloud_native_core_policy
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2014230
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v5.15-rc6&id=4785305c05b25a242e5314cc821f54ade4c18810
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v5.15-rc6&id=6457378fe796815c973f631a1904e147d6ee33b1
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/ipv4/route.c?h=v5.15-rc6&id=67d6d681e15b578c1725bad8ad079e05d1c48a8e
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/ipv6/route.c?h=v5.15-rc6&id=a00df2caffed3883c341d5685f830434312e4a43