CVE-2021-252168.1HighCWE-125

CVE-2021-25216: A second vulnerability in BIND's GSSAPI security policy negotiation can be targeted by a buffer overflow attack

ISC · BIND9

Vendor fix available · Affected: ISC BIND9 · Exploitation: likely to be exploited (10% or more)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

83.0%probability of exploitation in the next 30 days

99th percentile

050100

Higher than 99% of scored CVEs

8.1HighCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

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 products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

ISC · BIND9Open Source Branches 9.5 though 9.11 9.5.0 through versions…; Open Source Branches 9.12 though 9.16 9.12.0 through versio…; Supported Preview Branch 9.11-S 9.11.3-S1 through versions…; Supported Preview Branch 9.16-S 9.16.8-S1 through versions…; Development Branch 9.17 9.17.0 through versions before 9.17…

On the Atlas

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Open the Atlas

Exploitation: Likely to be exploited (10% or more). EPSS gives it a 10% or higher chance of exploitation in the next 30 days.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Out-of-bounds Read · Memory Corruption
Vendor: ISC
Published: April 2021
Band: Likely to be exploited (10% or more), April 2021

CoverageNo articles yet

No CyberSIXT article names CVE-2021-25216 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.