NULL pointer dereference in atftp - CVE-2019-11366
Published: April 20, 2019 / Updated: September 29, 2020
Vulnerability identifier: #VU47133
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2019-11366
CWE-ID: CWE-476
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Dennis Kaarsemaker
Affected software:
atftp
atftp
Detailed vulnerability description
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in atftpd in atftp 0.7.1. It does not lock the thread_list_mutex mutex before assigning the current thread data structure. As a result, the daemon is vulnerable to a denial of service attack due to a NULL pointer dereference. If thread_data is NULL when assigned to current, and modified by another thread before a certain tftpd_list.c check, there is a crash when dereferencing current->next. A remote attacker can perform a denial of service (DoS) attack.
How to mitigate CVE-2019-11366
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.
Sources
- 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/382f76a90b44f81fec00e2f609a94def4a5d3580/
- https://usn.ubuntu.com/4540-1/
- https://www.debian.org/security/2019/dsa-4438