SB2023100579 - Red Hat Enterprise Linux 8 update for glibc

Description

This security bulletin contains information about 4 secuirty vulnerabilities.

1) Out-of-bounds read (CVE-ID: CVE-2023-4527)

The vulnerability allows a remote attacker to gain access to potentially sensitive information or perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary condition within the getaddrinfo() function called with the AF_UNSPEC address family. A remote attacker with control over DNS server can send a DNS response via TCP larger than 2048 bytes, trigger an out-of-bounds read and crash the application or gain access to potentially sensitive information.

Successful exploitation of the vulnerability requires that system is configured with no-aaaa mode via /etc/resolv.conf.

2) Use-after-free (CVE-ID: CVE-2023-4806)

The vulnerability allows an attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a use-after-free error within the getaddrinfo() function. A remote attacker can perform a denial of service (DoS) attack.

3) Use-after-free (CVE-ID: CVE-2023-4813)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a use-after-free error within the gaih_inet() function when the getaddrinfo() function is called and the hosts database in /etc/nsswitch.conf is configured with SUCCESS=continue or SUCCESS=merge. A remote attacker can pass specially crafted data to the application and perform a denial of service (DoS) attack.

4) Buffer overflow (CVE-ID: CVE-2023-4911)

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

The vulnerability exists due to insufficient validation of GLIBC_TUNABLES environment variable. A local user can trigger memory corruption and execute arbitrary code with elevated privileges.

Remediation

Install update from vendor's website.

References

• https://access.redhat.com/errata/RHSA-2023:5455