#VU20420 Resource management error in Linux kernel - CVE-2019-15538

Vulnerability identifier: #VU20420

Vulnerability risk: Medium

CVSSv4.0: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-15538

CWE-ID: CWE-399

Exploitation vector: Local

Exploit availability: No

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

Vendor: Linux Foundation

Description

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

The vulnerability exists due to buggy implementation of quotas in "xfs_setattr_nonsize" in the "fs/xfs/xfs_iops.c" file. A local attacker can send specially crafted requests to the affected system and perform denial of service attack.

Note: This vulnerability can be exploited remotely, if XFS filesystem is exported for instance via NFS.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: 5.2.1 - 5.2.9

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External links
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=1fb254aa983bf190cfd685d40c64a480a9bafaee
https://github.com/torvalds/linux/commit/1fb254aa983bf190cfd685d40c64a480a9bafaee
https://lore.kernel.org/linux-xfs/20190823035528.GH1037422@magnolia/
https://lore.kernel.org/linux-xfs/20190823192433.GA8736@eldamar.local

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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.