Red Hat Enterprise Linux 7 update for bind

1) Reachable Assertion

EUVDB-ID: #VU28123

Risk: Medium

CVSSv4.0: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:A/U:Green]

CVE-ID: CVE-2020-8617

CWE-ID: CWE-617 - Reachable Assertion

Exploit availability: Yes

Description

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

The vulnerability exists due to a reachable assertion when checking validity of messages containing TSIG resource records within tsig.c. A remote attacker can send a specially crafted message and cause a BIND server to reach an inconsistent state if the attacker knows (or successfully guesses) the name of a TSIG key used by the server.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux EUS Compute Node: 7.7

Red Hat Enterprise Linux for x86_64 - Extended Update Support: 7.7

Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.7

Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 7.7

Red Hat Enterprise Linux Server - TUS: 7.7

Red Hat Enterprise Linux for Power, little endian - Extended Update Support: 7.7

Red Hat Enterprise Linux for Power, big endian - Extended Update Support: 7.7

Red Hat Enterprise Linux for IBM z Systems - Extended Update Support: 7.7

Red Hat Enterprise Linux Server - AUS: 7.7

bind (Red Hat package) main: before 9.11.4-9.P2.el7_7.1

CPE2.3

• cpe:2.3:o:red_hat:red_hat_enterprise_linux_eus_compute_node:7.7:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_x86_64_-_extended_update_support:7.7:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_update_services_for_sap_solutions:7.7:*:*:*:*:*:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_for_ibm_power_le_-_update_services_for_sap_solutions:7.7:*:*:*:*:*:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_tus:7.7:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_little_endian_-_extended_update_support:7.7:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_big_endian_-_extended_update_support:7.7:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems_-_extended_update_support:7.7:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_aus:7.7:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:bind_redhat_package:*:*:*:*:*:red_hat_enterprise_linux:*:*

External links

https://access.redhat.com/errata/RHSA-2020:2893

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. However, a fully functional exploit for this vulnerability is available.