SB2020111091 - openEuler 20.03 LTS update for bind

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Reachable Assertion (CVE-ID: CVE-2020-8622)

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

The vulnerability exists due to a reachable assertion when handling TSIG-signed request. An attacker on the network path for a TSIG-signed request, or operating the server receiving the TSIG-signed request, could send a truncated response to that request, triggering an assertion failure, causing the server to exit.

2) Reachable Assertion (CVE-ID: CVE-2020-8623)

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

The vulnerability exists due to a reachable assertion when processing DNS query for a zone signed with RSA. A remote attacker can send a specially crafted query and crash the DNS server.

Successful exploitation of the vulnerability requires that BIND is built with "--enable-native-pkcs11".

3) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2020-8624)

The vulnerability allows a remote user to perform unauthorized actions.

The vulnerability exists due to change 4885 in BIND inadvertently caused "update-policy" rules of type "subdomain" to be treated as if they were of type "zonesub", allowing updates to all parts of the zone along with the intended subdomain. A remote user with privileges to change a specific subset of the zone's content could abuse these unintended additional privileges to update other contents of the zone.

Remediation

Install update from vendor's website.

References

• https://www.openeuler.org/en/security/security-bulletins/detail/?id=openEuler-SA-2020-1081