CVE-2023-7192

Summary

A memory leak problem was found in ctnetlink_create_conntrack in net/netfilter/nf_conntrack_netlink.c in the Linux Kernel. This issue may allow a local attacker with CAP_NET_ADMIN privileges to cause a denial of service (DoS) attack due to a refcount overflow.

Affected Software

VendorProductVersion RangeStatus
Red HatRed Hat Enterprise Linux 8.2 Advanced Update Support0:4.18.0-193.133.1.el8_2 < *unaffected
Red HatRed Hat Enterprise Linux 8.2 Telecommunications Update Service0:4.18.0-193.133.1.rt13.184.el8_2 < *unaffected
Red HatRed Hat Enterprise Linux 8.2 Telecommunications Update Service0:4.18.0-193.133.1.el8_2 < *unaffected
Red HatRed Hat Enterprise Linux 8.2 Update Services for SAP Solutions0:4.18.0-193.133.1.el8_2 < *unaffected
Red HatRed Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support0:4.18.0-305.125.1.el8_4 < *unaffected
Red HatRed Hat Enterprise Linux 8.4 Telecommunications Update Service0:4.18.0-305.125.1.rt7.201.el8_4 < *unaffected
Red HatRed Hat Enterprise Linux 8.4 Telecommunications Update Service0:4.18.0-305.125.1.el8_4 < *unaffected
Red HatRed Hat Enterprise Linux 8.4 Update Services for SAP Solutions0:4.18.0-305.125.1.el8_4 < *unaffected
Red HatRed Hat Enterprise Linux 8.6 Extended Update Support0:4.18.0-372.95.1.el8_6 < *unaffected
Red HatRed Hat Enterprise Linux 8.8 Extended Update Support0:4.18.0-477.51.1.el8_8 < *unaffected
Red HatRed Hat Enterprise Linux 9.0 Extended Update Support0:5.14.0-70.93.2.el9_0 < *unaffected
Red HatRed Hat Enterprise Linux 9.0 Extended Update Support0:5.14.0-70.93.1.rt21.165.el9_0 < *unaffected
Red HatRed Hat Enterprise Linux 9.2 Extended Update Support0:5.14.0-284.52.1.el9_2 < *unaffected
Red HatRed Hat Enterprise Linux 9.2 Extended Update Support0:5.14.0-284.52.1.rt14.337.el9_2 < *unaffected
Red HatRed Hat Virtualization 4 for Red Hat Enterprise Linux 80:4.18.0-372.95.1.el8_6 < *unaffected

Weaknesses

  • CWE-401: Missing Release of Memory after Effective Lifetime

Workarounds

Triggering this issue requires the ability to create user/net namespaces.

On non-containerized deployments of Red Hat Enterprise Linux 8, you can disable user namespaces by setting user.max_user_namespaces to 0:

echo "user.max_user_namespaces=0" > /etc/sysctl.d/userns.conf

sysctl -p /etc/sysctl.d/userns.conf

On containerized deployments, such as Red Hat OpenShift Container Platform, do not use this mitigation as the functionality is needed to be enabled.

Alternatively, skip loading the affected netfilter module (i.e., nf_conntrack_netlink) onto the system until we have a fix available. This can be done by a blacklist mechanism which will ensure the driver is not loaded at boot time.

How do I blacklist a kernel module to prevent it from loading automatically?
https://access.redhat.com/solutions/41278

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References