A flaw named SegmentSmack was found in the way the Linux kernel handled specially crafted TCP packets. A remote attacker could use this flaw to trigger time and calculation expensive calls to tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() functions by sending specially modified packets within ongoing TCP sessions which could lead to a CPU saturation and hence a denial of service on the system. Maintaining the denial of service condition requires continuous two-way TCP sessions to a reachable open port, thus the attacks cannot be performed using spoofed IP addresses.
Find out more about CVE-2018-5390 from the MITRE CVE dictionary dictionary and NIST NVD.
Red Hat Product Security is aware of this issue. Updates will be released as they become available. For additional information, please refer to the Red Hat Knowledgebase article: https://access.redhat.com/articles/3553061
This issue affects the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 6, 7, its real-time kernel, Red Hat Enterprise MRG 2, Red Hat Enterprise Linux 7 for ARM 64, and Red Hat Enterprise Linux 7 for Power 9. Future kernel updates for the respective releases will address this issue.
This issue affects the Linux kernel packages as shipped with Red Hat Enterprise Linux 5, but to a lesser degree. As such, the issue severity for RHEL5 is considered Moderate. This is not currently planned to be addressed in future updates of the product due to its life cycle and the issue severity. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.
| CVSS3 Base Score | 7.5 |
|---|---|
| CVSS3 Base Metrics | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| Attack Vector | Network |
| Attack Complexity | Low |
| Privileges Required | None |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity Impact | None |
| Availability Impact | High |
| Platform | Errata | Release Date |
|---|---|---|
| Red Hat Enterprise Linux Server TUS (v. 7.2) (kernel) | RHSA-2018:2790 | 2018-09-25 |
| Red Hat Enterprise Linux 7 (kernel) | RHSA-2018:2384 | 2018-08-14 |
| Red Hat Enterprise Linux Extended Update Support 7.4 (kernel) | RHSA-2018:2776 | 2018-09-25 |
| Red Hat Enterprise Linux Advanced Update Support 6.5 (kernel) | RHSA-2018:2933 | 2018-10-16 |
| Red Hat Enterprise Linux Extended Update Support 6.7 (kernel) | RHSA-2018:2645 | 2018-09-04 |
| Red Hat Enterprise Linux Advanced Update Support 6.6 (kernel) | RHSA-2018:2924 | 2018-10-16 |
| Red Hat Enterprise Linux Advanced Update Support 7.2 (kernel) | RHSA-2018:2790 | 2018-09-25 |
| Red Hat Virtualization 4 Management Agent for RHEL 7 Hosts (redhat-release-virtualization-host) | RHSA-2018:2403 | 2018-08-15 |
| Red Hat Enterprise Linux Advanced Update Support 6.4 (kernel) | RHSA-2018:2791 | 2018-09-25 |
| Red Hat MRG Grid for RHEL 6 Server v.2 (kernel-rt) | RHSA-2018:2789 | 2018-09-25 |
| Red Hat Enterprise Linux 6 (kernel) | RHSA-2018:2390 | 2018-08-14 |
| Red Hat Enterprise Linux Extended Update Support 7.3 (kernel) | RHSA-2018:2785 | 2018-09-25 |
| Red Hat Enterprise Linux 7 (kernel-alt) | RHSA-2018:2948 | 2018-10-30 |
| Red Hat Enterprise Linux Server Update Services for SAP Solutions 7.2 (kernel) | RHSA-2018:2790 | 2018-09-25 |
| Red Hat Virtualization 4 Management Agent for RHEL 7 Hosts (rhvm-appliance) | RHSA-2018:2402 | 2018-08-16 |
| Red Hat Enterprise Linux Server TUS (v. 6.6) (kernel) | RHSA-2018:2924 | 2018-10-16 |
| Red Hat Enterprise Linux for Real Time for NFV (v. 7) (kernel-rt) | RHSA-2018:2395 | 2018-08-14 |
| Platform | Package | State |
|---|---|---|
| Red Hat Enterprise Linux 5 | kernel | Will not fix |
Vulmon