CVE-2021-25216
published 2021-04-29CVE-2021-25216: In BIND 9.5.0 -> 9.11.29, 9.12.0 -> 9.16.13, and versions BIND 9.11.3-S1 -> 9.11.29-S1 and 9.16.8-S1 -> 9.16.13-S1 of BIND Supported Preview Edition, as well…
PriorityP278critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
82.37%
99.6th percentile
In BIND 9.5.0 -> 9.11.29, 9.12.0 -> 9.16.13, and versions BIND 9.11.3-S1 -> 9.11.29-S1 and 9.16.8-S1 -> 9.16.13-S1 of BIND Supported Preview Edition, as well as release versions 9.17.0 -> 9.17.1 of the BIND 9.17 development branch, 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 values for the tkey-gssapi-keytab or tkey-gssapi-credential configuration 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. For servers that meet these conditions, the ISC SPNEGO implementation is vulnerable to various attacks, depending on the CPU architecture for which BIND was built: For named binaries compiled for 64-bit platforms, this flaw can be used to trigger a buffer over-read, leading to a server crash. For named binaries compiled for 32-bit platforms, this flaw can be used to trigger a server crash due to a buffer overflow and possibly also to achieve remote code execution. We have determined that standard SPNEGO implementations are available in the MIT and Heimdal Kerberos libraries, which support a broad range of operating systems, rendering the ISC implementation unnecessary and obsolete. Therefore, to reduce the attack surface for BIND users, we will be removing the ISC SPNEGO implementation in the April releases of BIND 9.11 and 9.16 (it had already been dropped from BIND 9.17). We would not normally remove something from a stable ESV (Extended Support Version) of BIND, but since system libraries can replace the ISC SPNEGO implementation, we have made an exception in this case for reasons of stability and security.
Affected
39 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | bind9 | < bind9 1:9.16.15-1 (bookworm) | bind9 1:9.16.15-1 (bookworm) |
| debian | debian_linux | — | — |
| debian | debian_linux | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | >= 9.0.0 < 9.11.31 | 9.11.31 |
| isc | bind | >= 9.12.0 < 9.16.15 | 9.16.15 |
| isc | bind | >= 9.17.0 < 9.17.12 | 9.17.12 |
| isc | bind9 | — | — |
| isc | bind9 | — | — |
Detection & IOCsextracted from sources · hover to see the quote
- →BIND is only vulnerable when explicitly configured with GSS-TSIG options; detect presence of 'tkey-gssapi-keytab' or 'tkey-gssapi-credential' in named configuration files to identify exposed instances ↗
- →On 32-bit BIND named binaries, the SPNEGO buffer overflow may enable remote code execution; prioritize detection and patching of 32-bit deployments ↗
- →On 64-bit BIND named binaries, exploitation results in a buffer over-read and server crash (DoS); monitor for unexpected named process crashes as a potential exploitation indicator ↗
- →Environments integrating BIND with Samba or Active Directory domain controllers are high-priority targets due to common GSS-TSIG usage in those configurations ↗
- ·The vulnerable code path is NOT exposed in BIND's default configuration; exploitation requires GSS-TSIG to be explicitly enabled via tkey-gssapi-keytab or tkey-gssapi-credential ↗
- ·Red Hat Enterprise Linux bind packages do not enable ISC SPNEGO and are therefore not affected, regardless of BIND version ↗
- ·Disabling GSS-TSIG features entirely (if another authentication mechanism is available for dynamic updates) is a viable mitigation ↗
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv2.06.8MEDIUMAV:N/AC:M/Au:N/C:P/I:P/A:P
osv9.8CRITICAL
vendor_msrc9.8CRITICAL
vendor_debian8.1HIGH
vendor_redhat8.1HIGH
vendor_ubuntu6.5MEDIUM
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GHSA
GHSA-4vh7-r4m9-4w3v: In BIND 9
ghsa_unreviewed·2022-05-24
CVE-2021-25216 [CRITICAL] CWE-125 GHSA-4vh7-r4m9-4w3v: In BIND 9
In BIND 9.5.0 -> 9.11.29, 9.12.0 -> 9.16.13, and versions BIND 9.11.3-S1 -> 9.11.29-S1 and 9.16.8-S1 -> 9.16.13-S1 of BIND Supported Preview Edition, as well as release versions 9.17.0 -> 9.17.1 of the BIND 9.17 development branch, 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 values for the tkey-gssapi-keytab or tkey-gssapi-credential configuration 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 Direct
OSV
CVE-2021-25216: In BIND 9
osv·2021-04-29·CVSS 9.8
CVE-2021-25216 [CRITICAL] CVE-2021-25216: In BIND 9
In BIND 9.5.0 -> 9.11.29, 9.12.0 -> 9.16.13, and versions BIND 9.11.3-S1 -> 9.11.29-S1 and 9.16.8-S1 -> 9.16.13-S1 of BIND Supported Preview Edition, as well as release versions 9.17.0 -> 9.17.1 of the BIND 9.17 development branch, 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 values for the tkey-gssapi-keytab or tkey-gssapi-credential configuration 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 Direct
OSV
bind9 vulnerabilities
osv·2021-04-29·CVSS 6.5
CVE-2021-25214 [MEDIUM] bind9 vulnerabilities
bind9 vulnerabilities
Greg Kuechle discovered that Bind incorrectly handled certain incremental
zone updates. A remote attacker could possibly use this issue to cause Bind
to crash, resulting in a denial of service. (CVE-2021-25214)
Siva Kakarla discovered that Bind incorrectly handled certain DNAME
records. A remote attacker could possibly use this issue to cause Bind to
crash, resulting in a denial of service. (CVE-2021-25215)
It was discovered that Bind incorrectly handled GSSAPI security policy
negotiation. A remote attacker could use this issue to cause Bind to crash,
resulting in a denial of service, or possibly execute arbitrary code.
(CVE-2021-25216)
Ubuntu
Bind vulnerabilities
vendor_ubuntu·2025-09-08·CVSS 6.5
CVE-2021-25215 [MEDIUM] Bind vulnerabilities
Title: Bind vulnerabilities
Summary: Several security issues were fixed in Bind.
Greg Kuechle discovered that Bind incorrectly handled certain incremental
zone updates. A remote attacker could possibly use this issue to cause Bind
to crash, resulting in a denial of service. (CVE-2021-25214)
Siva Kakarla discovered that Bind incorrectly handled certain DNAME
records. A remote attacker could possibly use this issue to cause Bind to
crash, resulting in a denial of service. (CVE-2021-25215)
It was discovered that Bind incorrectly handled GSSAPI security policy
negotiation. A remote attacker could use this issue to cause Bind to crash,
resulting in a denial of service, or possibly execute arbitrary code.
(CVE-2021-25216)
Instructions: In general, a standard system update will make all the
CISA ICS
Siemens SINEC INS
cisa_ics·2022-03-10·CVSS 5.9
[MEDIUM] Siemens SINEC INS
## Archived Content In an effort to keep CISA.gov current, the archive contains outdated information that may not reflect current policy or programs.
ICS Advisory
##
Siemens SINEC INS
Last RevisedMarch 10, 2022
Alert CodeICSA-22-069-09
## 1. EXECUTIVE SUMMARY
- CVSS v3 9.8
- ATTENTION: Exploitable remotely/low attack complexity
- Vendor: Siemens
- Equipment: SINEC INS
- Vulnerability: Using Components with Known Vulnerabilities
## 2. RISK EVALUATION
Successful exploitation of this vulnerability in third-party components could allow an attacker to interfere with the affected product in various ways.
## 3. TECHNICAL DETAILS
## 3.1 AFFECTED PRODUCTS
Siemens reports this vulnerability affects the following SINEC INS (Infrastructure Netw
Red Hat
bind: Vulnerability in BIND's GSSAPI security policy negotiation can be targeted by a buffer overflow attack
vendor_redhat·2021-04-28·CVSS 8.1
CVE-2021-25216 [HIGH] CWE-131 bind: Vulnerability in BIND's GSSAPI security policy negotiation can be targeted by a buffer overflow attack
bind: Vulnerability in BIND's GSSAPI security policy negotiation can be targeted by a buffer overflow attack
In BIND 9.5.0 -> 9.11.29, 9.12.0 -> 9.16.13, and versions BIND 9.11.3-S1 -> 9.11.29-S1 and 9.16.8-S1 -> 9.16.13-S1 of BIND Supported Preview Edition, as well as release versions 9.17.0 -> 9.17.1 of the BIND 9.17 development branch, 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 values for the tkey-gssapi-keytab or tkey-gssapi-credential configuration options. Although the default configuration is not vulnerable, GSS-TSIG is frequently used in networks where BIND
Microsoft
A second vulnerability in BIND's GSSAPI security policy negotiation can be targeted by a buffer overflow attack
vendor_msrc·2021-04-13·CVSS 9.8
CVE-2021-25216 [HIGH] CWE-125 A second vulnerability in BIND's GSSAPI security policy negotiation can be targeted by a buffer overflow attack
A second vulnerability in BIND's GSSAPI security policy negotiation can be targeted by a buffer overflow attack
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.
Mariner: Mariner
isc: isc
Customer Action Required: Yes
Remedia
Debian
CVE-2021-25216: bind9 - In BIND 9.5.0 -> 9.11.29, 9.12.0 -> 9.16.13, and versions BIND 9.11.3-S1 -> 9.11...
vendor_debian·2021·CVSS 8.1
CVE-2021-25216 [HIGH] CVE-2021-25216: bind9 - In BIND 9.5.0 -> 9.11.29, 9.12.0 -> 9.16.13, and versions BIND 9.11.3-S1 -> 9.11...
In BIND 9.5.0 -> 9.11.29, 9.12.0 -> 9.16.13, and versions BIND 9.11.3-S1 -> 9.11.29-S1 and 9.16.8-S1 -> 9.16.13-S1 of BIND Supported Preview Edition, as well as release versions 9.17.0 -> 9.17.1 of the BIND 9.17 development branch, 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 values for the tkey-gssapi-keytab or tkey-gssapi-credential configuration 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 Direct
No detection rules found.
No public exploits indexed.
http://www.openwall.com/lists/oss-security/2021/04/29/1http://www.openwall.com/lists/oss-security/2021/04/29/2http://www.openwall.com/lists/oss-security/2021/04/29/3http://www.openwall.com/lists/oss-security/2021/04/29/4https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdfhttps://kb.isc.org/v1/docs/cve-2021-25215https://lists.debian.org/debian-lts-announce/2021/05/msg00001.htmlhttps://security.netapp.com/advisory/ntap-20210521-0006/https://www.debian.org/security/2021/dsa-4909https://www.zerodayinitiative.com/advisories/ZDI-21-657/http://www.openwall.com/lists/oss-security/2021/04/29/1http://www.openwall.com/lists/oss-security/2021/04/29/2http://www.openwall.com/lists/oss-security/2021/04/29/3http://www.openwall.com/lists/oss-security/2021/04/29/4https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdfhttps://kb.isc.org/v1/docs/cve-2021-25215https://lists.debian.org/debian-lts-announce/2021/05/msg00001.htmlhttps://security.netapp.com/advisory/ntap-20210521-0006/https://www.debian.org/security/2021/dsa-4909https://www.zerodayinitiative.com/advisories/ZDI-21-657/
2021-04-29
Published