#VU9775 Improper input validation in Linux kernel - CVE-2017-17805

Vulnerability identifier: #VU9775

Vulnerability risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2017-17805

CWE-ID: CWE-20

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 cause DoS condition on the target system.

The weakness exists due to the Salsa20 encryption algorithm in the Linux kernel does not correctly handle zero-length inputs. A local attacker able to use the AF_ALG-based skcipher interface (CONFIG_CRYPTO_USER_API_SKCIPHER) can trigger uninitialized-memory free and cause the kernel to crash or execute a specially crafted sequence of system calls that use the blkcipher_walk API.

Successful exploitation of the vulnerability results in denial of service.

Mitigation
Update to version 4.14.8.

Vulnerable software versions

Linux kernel: 4.10.0 - 4.14.7

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External links
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ecaaab5649781c5a0effda...

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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.