Ubuntu update for Bind



| Updated: 2020-05-21
Risk High
Patch available YES
Number of vulnerabilities 2
CVE-ID CVE-2020-8616
CVE-2020-8617
CWE-ID CWE-399
CWE-617
Exploitation vector Network
Public exploit Public exploit code for vulnerability #2 is available.
Vulnerable software
 bind9 (Ubuntu package)
Operating systems & Components / Operating system package or component

Vendor Canonical Ltd.

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Resource management error

EUVDB-ID: #VU28121

Risk: High

CVSSv4.0: 6.6 [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:U/U:Amber]

CVE-ID: CVE-2020-8616

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: No

Description

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

The vulnerability exists due to improper management of internal resources with the applicatoin. In order for a server performing recursion to locate records in the DNS graph it must be capable of processing referrals, such as those received when it attempts to query an authoritative server for a record which is delegated elsewhere. A malicious actor who intentionally exploits this lack of effective limitation on the number of fetches performed when processing referrals can, through the use of specially crafted referrals, cause a recursing server to issue a very large number of fetches in an attempt to process the referral.

Mitigation

Update the affected packages.

Ubuntu 20.04 LTS
bind9 - 1:9.16.1-0ubuntu2.1
Ubuntu 19.10
bind9 - 1:9.11.5.P4+dfsg-5.1ubuntu2.2
Ubuntu 18.04 LTS
bind9 - 1:9.11.3+dfsg-1ubuntu1.12
Ubuntu 16.04 LTS
bind9 - 1:9.10.3.dfsg.P4-8ubuntu1.16

Vulnerable software versions

bind9 (Ubuntu package): 1:9.1.0-1 - 1:9.16.1-0ubuntu2

CPE2.3 External links

https://usn.ubuntu.com/4365-1/


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.

2) 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

Update the affected packages.

Ubuntu 20.04 LTS
bind9 - 1:9.16.1-0ubuntu2.1
Ubuntu 19.10
bind9 - 1:9.11.5.P4+dfsg-5.1ubuntu2.2
Ubuntu 18.04 LTS
bind9 - 1:9.11.3+dfsg-1ubuntu1.12
Ubuntu 16.04 LTS
bind9 - 1:9.10.3.dfsg.P4-8ubuntu1.16

Vulnerable software versions

bind9 (Ubuntu package): 1:9.1.0-1 - 1:9.16.1-0ubuntu2

CPE2.3 External links

https://usn.ubuntu.com/4365-1/


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.



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