#VU27338 Buffer overflow in musl libc - CVE-2017-15650

Vulnerability identifier: #VU27338

Vulnerability risk: High

CVSSv4.0: 6.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2017-15650

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
musl libc
Universal components / Libraries / Libraries used by multiple products

Vendor: GNU

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary when processing DNS replies in dns_parse_callback(0 function in network/lookup_name.c. A remote attacker can send an unexpected number by sending A records in a reply to an AAAA query, trigger memory corruption and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

musl libc: 0.5.0 - 1.1.16

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External links
https://git.musl-libc.org/cgit/musl/commit/?id=45ca5d3fcb6f874bf5ba55d0e9651cef68515395
https://git.musl-libc.org/cgit/musl/tree/WHATSNEW
https://openwall.com/lists/oss-security/2017/10/19/5

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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