CVE-2020-1749: High severity Linux Linux kernel vulnerability
A flaw was found in the Linux kernel's implementation of some networking protocols in IPsec, such as VXLAN and GENEVE tunnels over IPv6. When an encrypted tunnel is created between two hosts, the kernel isn't correctly routing tunneled data over the encrypted link; rather sending the data unencrypted. This would allow anyone in between the two endpoints to read the traffic unencrypted. The main threat from this vulnerability is to data confidentiality.
Other sources
A flaw was found in the Linux kernels implementation of some networking protocols in encrypted IPsec tunnels.
The most common use cases are VXLAN or GENEVE tunnels over IPv6. When an encrypted tunnel is created between two hosts, the kernel will not correctly route this tunneled data over the encrypted link but instead will send the data unencrypted.
This could allow this information to be intercepted by a Man In the Middle (MITM) attack by an attacker with control over viewing contents between the two connection endpoints.
Fixed in: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=6c8991f41546
Introduced in: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=5f81bd2e5d80
— Red Hat
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
redhat/kernel-rtto a version that resolves this vulnerability.Fixed in 0:3.10.0-1160.rt56.1131.el7 - Upgrade
Upgrade
redhat/kernelto a version that resolves this vulnerability.Fixed in 0:3.10.0-1160.el7 - Upgrade
Upgrade
redhat/kernel-altto a version that resolves this vulnerability.Fixed in 0:4.14.0-115.35.1.el7a - Upgrade
Upgrade
redhat/kernel-rtto a version that resolves this vulnerability.Fixed in 0:4.18.0-193.rt13.51.el8 - Upgrade
Upgrade
redhat/kernelto a version that resolves this vulnerability.Fixed in 0:4.18.0-193.el8 - Upgrade
Upgrade
redhat/Linux kernel versionto a version that resolves this vulnerability.Fixed in 5.5 - Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 5.10.223-1Fixed in 5.10.262-1Fixed in 6.1.176-1Fixed in 6.1.180-1Fixed in 6.12.94-1Fixed in 6.12.101-1Fixed in 7.1.7-1Fixed in 7.1.8-1 - Configuration
Disable the IPV6 protocol as a workaround for affected systems that do not require IPv6; if IPv6 is not in use this flaw will not be triggered.
Linux kernel IPsec (networking protocols over IPv6) IPv6 protocol = disable
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is the severity of CVE-2020-1749?
CVE-2020-1749 is classified as a medium severity vulnerability.
How do I fix CVE-2020-1749?
To fix CVE-2020-1749, update your Linux kernel to the recommended versions provided by your distribution.
What systems are affected by CVE-2020-1749?
CVE-2020-1749 affects various versions of the Linux kernel, particularly in Red Hat Enterprise Linux 7 and 8.
What is the nature of the vulnerability in CVE-2020-1749?
CVE-2020-1749 involves improper handling of networking protocols in IPsec, leading to potential unencrypted data transmission.
Can CVE-2020-1749 be exploited remotely?
Yes, CVE-2020-1749 could potentially be exploited remotely if an attacker has access to a vulnerable network.