#VU47132 Out-of-bounds write in atftp - CVE-2019-11365

Vulnerability identifier: #VU47132

Vulnerability risk: High

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2019-11365

CWE-ID: CWE-787

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
atftp
Web applications / Modules and components for CMS

Vendor: Dennis Kaarsemaker

Description

The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.

An issue was discovered in atftpd in atftp 0.7.1. A remote attacker may send a crafted packet triggering a stack-based buffer overflow due to an insecurely implemented strncpy call. The vulnerability is triggered by sending an error packet of 3 bytes or fewer. There are multiple instances of this vulnerable strncpy pattern within the code base, specifically within tftpd_file.c, tftp_file.c, tftpd_mtftp.c, and tftp_mtftp.c.

Mitigation
Install update from vendor's website.

Vulnerable software versions

atftp: 0.7.1

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External links
https://lists.debian.org/debian-lts-announce/2019/05/msg00012.html
https://pulsesecurity.co.nz/advisories/atftpd-multiple-vulnerabilities
https://seclists.org/bugtraq/2019/May/16
https://security.gentoo.org/glsa/202003-14
https://sourceforge.net/p/atftp/code/ci/abed7d245d8e8bdfeab24f9f7f55a52c3140f96b/
https://usn.ubuntu.com/4540-1/
https://www.debian.org/security/2019/dsa-4438

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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.