Debian update for bind9
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 4 |
| CVE-ID | CVE-2020-8619 CVE-2020-8622 CVE-2020-8623 CVE-2020-8624 |
| CWE-ID | CWE-617 CWE-264 |
| Exploitation vector | Network |
| Public exploit | N/A |
| Vulnerable software Subscribe |
bind9 (Debian package) Operating systems & Components / Operating system package or component |
| Vendor | Debian |
Security Bulletin
This security bulletin contains information about 4 vulnerabilities.
1) Reachable Assertion
EUVDB-ID: #VU29151
Risk: Medium
CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2020-8619
CWE-ID:
CWE-617 - Reachable Assertion
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a reachable assertion when processing entries with an asterisk ("*") character in rbtdb.c. Unless a nameserver is providing authoritative service for one or more zones and at least one zone contains an empty non-terminal entry containing an asterisk ("*") character, an attacker with ability to change zone content can trigger assertion failure and perform a denial of service (DoS) attack.
Note, this vulnerability may affect hosting provider that allow users access to domain management functionality.
Update bind9 package to version 1:9.11.5.P4+dfsg-5.1+deb10u2.
Vulnerable software versionsbind9 (Debian package): 1:9.11.5.P4+dfsg-5.1+deb10u1 - 9.11.5.P4+dfsg-5.1+deb10u2
External linkshttp://www.debian.org/security/2020/dsa-4752
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user 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: #VU45819
Risk: Medium
CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2020-8622
CWE-ID:
CWE-617 - Reachable Assertion
Exploit availability: No
DescriptionThe 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.
MitigationUpdate bind9 package to version 1:9.11.5.P4+dfsg-5.1+deb10u2.
Vulnerable software versionsbind9 (Debian package): 1:9.11.5.P4+dfsg-5.1+deb10u1 - 9.11.5.P4+dfsg-5.1+deb10u2
External linkshttp://www.debian.org/security/2020/dsa-4752
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
3) Reachable Assertion
EUVDB-ID: #VU45818
Risk: Medium
CVSSv3.1: 5.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2020-8623
CWE-ID:
CWE-617 - Reachable Assertion
Exploit availability: No
DescriptionThe 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".
MitigationUpdate bind9 package to version 1:9.11.5.P4+dfsg-5.1+deb10u2.
Vulnerable software versionsbind9 (Debian package): 1:9.11.5.P4+dfsg-5.1+deb10u1 - 9.11.5.P4+dfsg-5.1+deb10u2
External linkshttp://www.debian.org/security/2020/dsa-4752
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.
4) Permissions, Privileges, and Access Controls
EUVDB-ID: #VU45817
Risk: Low
CVSSv3.1: 3.8 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2020-8624
CWE-ID:
CWE-264 - Permissions, Privileges, and Access Controls
Exploit availability: No
DescriptionThe 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.
MitigationUpdate bind9 package to version 1:9.11.5.P4+dfsg-5.1+deb10u2.
Vulnerable software versionsbind9 (Debian package): 1:9.11.5.P4+dfsg-5.1+deb10u1 - 9.11.5.P4+dfsg-5.1+deb10u2
External linkshttp://www.debian.org/security/2020/dsa-4752
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
