High [CVE-2021-20322] flaw in the processing of received ICMP errors (ICMP fragment needed and ICMP redirect) in the Linux kernel functionality was…
This high-severity Red Hat Linux advisory covers CVE-2021-20322 affecting Red Hat Enterprise Linux 8.4 Extended Update Support, Red Hat Enterprise Linux 5, Red Hat Enterprise Linux 6.
Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.
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Summary
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. This issue is rated as having Moderate impact because of the attack scenario limitation.
It is possible to harm the networking services only, but not for the overall system under attack, and impossible to get access to this remote system under attack. Red Hat severity: Moderate — CVSS 7.4 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N).
Weakness: CWE-330. Affected Red Hat products: Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 8.4 Extended Update Support; Red Hat Enterprise Linux 5; Red Hat Enterprise Linux 6; Red Hat Enterprise Linux 7.
Red Hat lists Red Hat Enterprise Linux 9 as not affected. Will not fix / out of support: Red Hat Enterprise Linux 5; Red Hat Enterprise Linux 6; Red Hat Enterprise Linux 7.
Red Hat fixing advisory: RHSA-2022:1975, RHSA-2022:1988, RHSA-2022:4835, RHSA-2022:4829.
Affected products named by the advisory: Red Hat package: kernel-rt.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · high-confidence parse· fetched 17 days ago·verify at source
- kernel-rt-0:4.18.0-372.9.1.rt7.166.el8
- kernel-0:4.18.0-372.9.1.el8
- kernel-rt-0:4.18.0-305.49.1.rt7.121.el8_4
- kernel-0:4.18.0-305.49.1.el8_4
- RHSA-2022:1975
- RHSA-2022:1988
- RHSA-2022:4835
- RHSA-2022:4829
Official advisory · high-confidence parse· fetched 17 days ago·verify at source
Mitigation checklist
- Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Official advisory · high-confidence parse· fetched 17 days ago·verify at source
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