Vulnerability identifier: #VU30426

Vulnerability risk: Low

CVSSv3.1: 4.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-20422

CWE-ID: N/A

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a local authenticated user to perform a denial of service (DoS) attack.

In the Linux kernel before 5.3.4, fib6_rule_lookup in net/ipv6/ip6_fib.c mishandles the RT6_LOOKUP_F_DST_NOREF flag in a reference-count decision, leading to (for example) a crash that was identified by syzkaller, aka CID-7b09c2d052db.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 5.3.1 - 5.3.3

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External links
http://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.3.4
http://github.com/torvalds/linux/commit/7b09c2d052db4b4ad0b27b97918b46a7746966fa
http://security.netapp.com/advisory/ntap-20200313-0003/

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.