It was found that the RFC 5961 challenge ACK rate limiting as implemented in the Linux kernel's networking subsystem allowed an off-path attacker to leak certain information about a given connection by creating congestion on the global challenge ACK rate limit counter and then measuring the changes by probing packets. An off-path attacker could use this flaw to either terminate TCP connection and/or inject payload into non-secured TCP connection between two endpoints on the network.
Find out more about CVE-2016-5696 from the MITRE CVE dictionary dictionary and NIST NVD.
This issue does not affect the Linux kernels as shipped with Red Hat Enterprise Linux 4 and 5.
| Base Score | 5.8 |
|---|---|
| Base Metrics | AV:N/AC:M/Au:N/C:N/I:P/A:P |
| Access Vector | Network |
| Access Complexity | Medium |
| Authentication | None |
| Confidentiality Impact | None |
| Integrity Impact | Partial |
| Availability Impact | Partial |
| CVSS3 Base Score | 4.8 |
|---|---|
| CVSS3 Base Metrics | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L |
| Attack Vector | Network |
| Attack Complexity | High |
| Privileges Required | None |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity Impact | Low |
| Availability Impact | Low |
Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).
| Platform | Errata | Release Date |
|---|---|---|
| Red Hat Enterprise Linux for Real Time for NFV (v. 7) (kernel-rt) | RHSA-2016:1632 | 2016-08-18 |
| Red Hat Enterprise Linux 6 (kernel) | RHSA-2016:1664 | 2016-08-23 |
| Red Hat Enterprise Linux Extended Update Support 6.6 (kernel) | RHSA-2016:1939 | 2016-09-27 |
| Red Hat Enterprise Linux 7 (kernel) | RHSA-2016:1633 | 2016-08-18 |
| Red Hat MRG Grid for RHEL 6 Server v.2 (kernel-rt) | RHSA-2016:1631 | 2016-08-18 |
| Red Hat Enterprise Linux Extended Update Support 7.1 (kernel) | RHSA-2016:1657 | 2016-08-23 |
| Red Hat Enterprise Linux Advanced Update Support 6.5 (kernel) | RHSA-2016:1814 | 2016-09-06 |
| Red Hat Enterprise Linux Extended Update Support 6.7 (kernel) | RHSA-2016:1815 | 2016-09-06 |
| Platform | Package | State |
|---|---|---|
| Red Hat Enterprise Linux 5 | kernel | Not affected |
| Red Hat Enterprise Linux 4 | kernel | Not affected |
Vulmon