SB2020031416 - Gentoo update for atftp

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) Out-of-bounds write (CVE-ID: CVE-2019-11365)

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.

2) NULL pointer dereference (CVE-ID: CVE-2019-11366)

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.

Remediation

Install update from vendor's website.

References

• https://security.gentoo.org/
• https://security.gentoo.org/glsa/202003-14