CVE-2021-47291: linux kernel vulnerability

What is known

In the Linux kernel, the following vulnerability has been resolved: ipv6: fix another slab-out-of-bounds in fib6_nh_flush_exceptions While running the self-tests on a KASAN enabled kernel, I observed a slab-out-of-bounds splat very similar to the one reported in commit 821bbf79fe46 ("ipv6: Fix KASAN: slab-out-of-bounds Read in fib6_nh_flush_exceptions"). We additionally need to take care of fib6_metrics initialization failure when the caller provides an nh. The fix is similar, explicitly free the route instead of calling fib6_info_release on a half-initialized object.

Business impact

Successful exploitation of CVE-2021-47291, a high vulnerability (CVSS 7.8) affecting linux kernel, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether linux kernel is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

• NVD
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