CVE-2020-8625 | A vulnerability in BIND's GSSAPI security policy negotiation can be targeted by a buffer overflow attack

BIND servers are vulnerable if they are running an affected version and are configured to use GSS-TSIG features. In a configuration which uses BIND's default settings the vulnerable code path is not exposed, but a server can be rendered vulnerable by explicitly setting valid values for the tkey-gssapi-keytab or tkey-gssapi-credentialconfiguration options. Although the default configuration is not vulnerable, GSS-TSIG is frequently used in networks where BIND is integrated with Samba, as well as in mixed-server environments that combine BIND servers with Active Directory domain controllers. The most likely outcome of a successful exploitation of the vulnerability is a crash of the named process. However, remote code execution, while unproven, is theoretically possible. Affects: BIND 9.5.0 -> 9.11.27, 9.12.0 -> 9.16.11, and versions BIND 9.11.3-S1 -> 9.11.27-S1 and 9.16.8-S1 -> 9.16.11-S1 of BIND Supported Preview Edition. Also release versions 9.17.0 -> 9.17.1 of the BIND 9.17 development branch

Published: 2021-02-17 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2020-8625 is rated Moderate Risk (64.9/100): CVSS High severity, with high exploitation likelihood (EPSS 25.15%, 96th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-8625

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-01 26.30% 25.15% -1.15%
2 2026-03-04 40.16% 26.30% -13.86%
3 2026-03-03 40.16%

Full EPSS history (61 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-8625

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.2 5.9 [email protected]
8.1 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.2 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
8.6 6.4 [email protected]

Weakness enumeration for CVE-2020-8625

OS Trackers for CVE-2020-8625

vendor priority summary link
alpine high CVE-2020-8625: 1 source package rows (bind); 78 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 10, open 68. https://security.alpinelinux.org/vuln/CVE-2020-8625
debian not yet assigned CVE-2020-8625 not yet assigned priority: Debian including 1 source packages (bind9), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-8625
redhat high https://access.redhat.com/security/cve/CVE-2020-8625
suse high CVE-2020-8625 severity important: SUSE including 363 source package names (amazon/suse-sles-15-sp1-chost-byos-v20210304-hvm-ssd-x86_64, amazon/suse-sles-15-sp1-chost-byos-v20220127-hvm-ssd-x86_64, …), 941 product×package rows across 80 product lines (HPE Helion OpenStack 8, Image SLES12-SP5-Azure-BYOS, … (80 product lines)): Fixed 737, Known Affected 204. https://www.suse.com/security/cve/CVE-2020-8625/
ubuntu medium CVE-2020-8625 medium priority: Ubuntu including 1 source packages (bind9), 6 status rows across 6 suites (bionic, focal, groovy, trusty, upstream, xenial): released 6. https://ubuntu.com/security/CVE-2020-8625

Affected software / configurations for CVE-2020-8625

Vendor Product Version Raw CPE
isc bind >= 9.5.0, <= 9.11.27 cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*
isc bind >= 9.12.0, <= 9.16.11 cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*
isc bind 9.11.3 cpe:2.3:a:isc:bind:9.11.3:s1:*:*:supported_preview:*:*:*
isc bind 9.11.5 cpe:2.3:a:isc:bind:9.11.5:s3:*:*:supported_preview:*:*:*
isc bind 9.11.5 cpe:2.3:a:isc:bind:9.11.5:s5:*:*:supported_preview:*:*:*
isc bind 9.11.6 cpe:2.3:a:isc:bind:9.11.6:s1:*:*:supported_preview:*:*:*
isc bind 9.11.7 cpe:2.3:a:isc:bind:9.11.7:s1:*:*:supported_preview:*:*:*
isc bind 9.11.8 cpe:2.3:a:isc:bind:9.11.8:s1:*:*:supported_preview:*:*:*
isc bind 9.11.21 cpe:2.3:a:isc:bind:9.11.21:s1:*:*:supported_preview:*:*:*
isc bind 9.11.27 cpe:2.3:a:isc:bind:9.11.27:s1:*:*:supported_preview:*:*:*
isc bind 9.16.8 cpe:2.3:a:isc:bind:9.16.8:s1:*:*:supported_preview:*:*:*
isc bind 9.16.11 cpe:2.3:a:isc:bind:9.16.11:s1:*:*:supported_preview:*:*:*
isc bind 9.17.0 cpe:2.3:a:isc:bind:9.17.0:*:*:*:*:*:*:*
isc bind 9.17.1 cpe:2.3:a:isc:bind:9.17.1:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
fedoraproject fedora 33 cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
siemens sinec_infrastructure_network_services < 1.0.1.1 cpe:2.3:a:siemens:sinec_infrastructure_network_services:*:*:*:*:*:*:*:*
netapp cloud_backup cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:*
netapp a250_firmware cpe:2.3:o:netapp:a250_firmware:-:*:*:*:*:*:*:*
netapp 500f_firmware cpe:2.3:o:netapp:500f_firmware:-:*:*:*:*:*:*:*

References for CVE-2020-8625

URL Tags
http://www.openwall.com/lists/oss-security/2021/02/19/1 Mailing List Patch Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/02/20/2 Mailing List Patch Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf Patch Third Party Advisory
https://kb.isc.org/v1/docs/cve-2020-8625 Mitigation Vendor Advisory
https://lists.debian.org/debian-lts-announce/2021/02/msg00029.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EBTPWRQWRQEJNWY4NHO4WLS4KLJ3ERHZ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KYXAF7G45RXDVNUTWWCI2CVTHRZ67LST/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QWCMBOSZOJIIET7BWTRYS3HLX5TSDKHX/
https://security.netapp.com/advisory/ntap-20210319-0001/ Third Party Advisory
https://www.debian.org/security/2021/dsa-4857 Third Party Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-195/ Third Party Advisory VDB Entry
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