ISC BIND 9 up to 9.16.50-S1/9.18.37-S1/9.20.9/9.20.10-S1 ECS Options acceptance of extraneous untrusted data with trusted data

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.8$0-$5k0.00

Summaryinfo

A vulnerability was found in ISC BIND 9 up to 9.16.50-S1/9.18.37-S1/9.20.9/9.20.10-S1 and classified as problematic. The affected element is an unknown function of the component ECS Options Handler. Such manipulation leads to acceptance of extraneous untrusted data with trusted data. This vulnerability is documented as CVE-2025-40776. The attack can be executed remotely. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in ISC BIND 9 up to 9.16.50-S1/9.18.37-S1/9.20.9/9.20.10-S1. Affected by this issue is an unknown code of the component ECS Options Handler. The manipulation with an unknown input leads to a acceptance of extraneous untrusted data with trusted data vulnerability. Using CWE to declare the problem leads to CWE-349. The product, when processing trusted data, accepts any untrusted data that is also included with the trusted data, treating the untrusted data as if it were trusted. Impacted is integrity. CVE summarizes:

A `named` caching resolver that is configured to send ECS (EDNS Client Subnet) options may be vulnerable to a cache-poisoning attack. This issue affects BIND 9 versions 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.37-S1, and 9.20.9-S1 through 9.20.10-S1.

The advisory is available at kb.isc.org. This vulnerability is handled as CVE-2025-40776 since 04/16/2025. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 02/16/2026).

The vulnerability scanner Nessus provides a plugin with the ID 298818 (ISC BIND 9.11.3-S1 < 9.18.38-S1 / 9.18.11-S1 < 9.18.38-S1 / 9.20.9-S1 < 9.20.11-S1 Vulnerability (cve-2025-40776)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 9.20.10 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (298818) and CERT Bund (WID-SEC-2025-1585). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

  • Internet Systems Consortium BIND

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.9
VulDB Meta Temp Score: 6.8

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.6
CNA Vector (isc): 🔒

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Acceptance of extraneous untrusted data with trusted data
CWE: CWE-349
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 298818
Nessus Name: ISC BIND 9.11.3-S1 < 9.18.38-S1 / 9.18.11-S1 < 9.18.38-S1 / 9.20.9-S1 < 9.20.11-S1 Vulnerability (cve-2025-40776)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: BIND 9 9.20.10

Timelineinfo

04/16/2025 CVE reserved
07/16/2025 +91 days Advisory disclosed
07/16/2025 +0 days VulDB entry created
02/16/2026 +215 days VulDB entry last update

Sourcesinfo

Vendor: isc.org

Advisory: kb.isc.org
Status: Confirmed

CVE: CVE-2025-40776 (🔒)
GCVE (CVE): GCVE-0-2025-40776
GCVE (VulDB): GCVE-100-316586
CERT Bund: WID-SEC-2025-1585 - Internet Systems Consortium BIND: Mehrere Schwachstellen

Entryinfo

Created: 07/16/2025 16:13
Updated: 02/16/2026 02:00
Changes: 07/16/2025 16:13 (64), 07/17/2025 11:23 (7), 02/16/2026 02:00 (2)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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