SB2021070711 - Gentoo update for GLib

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Incorrect Conversion between Numeric Types (CVE-ID: CVE-2021-27218)

The vulnerability allows a local user to bypass implemented security restrictions.

The vulnerability exists due to incorrect conversion between numeric types in Gnome Glib. If g_byte_array_new_take() was called with a buffer of 4GB or more on a 64-bit platform, the length would be truncated modulo 2**32, causing unintended length truncation.

2) Integer overflow (CVE-ID: CVE-2021-27219)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to integer overflow within the g_bytes_new() function on 64-bit platforms due to an implicit cast from 64 bits to 32 bits. A local user can run a specially crafted program to trigger an integer overflow and execute arbitrary code with elevated privileges.

3) UNIX symbolic link following (CVE-ID: CVE-2021-28153)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a symlink following issue, when g_file_replace() is used with G_FILE_CREATE_REPLACE_DESTINATION. A local user can create a specially crafted symbolic link to a critical file on the system and overwrite it with privileges of the application.

Successful exploitation of this vulnerability may result in privilege escalation.

Remediation

Install update from vendor's website.

References

• https://security.gentoo.org/
• https://security.gentoo.org/glsa/202107-13