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CVE-2021-25220

DNS forwarders - cache poisoning vulnerability

No known exploitation. EPSS puts it in the 88th percentile. A vendor fix is available.

CVSS 3.16.8MediumEPSS percentile88th3.4% chance in 30 daysCISA KEVNot listedNo confirmed exploitation
No public exploit knownFixVendor fixNo build named by the sources

Published Updated Sources: CVE.org, NVD, BDU, CSAF

NVD CVE.org

What to do

The vendor has published a fix. Version details are below where the sources state them.

Check it yourselfA free OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Request an assessment to establish which checks fit your systems.

What it is

From the CVE record

BIND 9.11.0 -> 9.11.36 9.12.0 -> 9.16.26 9.17.0 -> 9.18.0 BIND Supported Preview Editions: 9.11.4-S1 -> 9.11.36-S1 9.16.8-S1 -> 9.16.26-S1 Versions of BIND 9 earlier than those shown - back to 9.1.0, including Supported Preview Editions - are also believed to be affected but have not been tested as they are EOL. The cache could become poisoned with incorrect records leading to queries being made to the wrong servers, which might also result in false information being returned to clients.

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS88th
CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

3.4% chance of exploitation activity in the next 30 days, which ranks it in the 88th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

7 events over 1555 days, from the signal feeds we watch.

  1. OpenVAS check added
  2. Patch availableworkaround available, record updated
  3. Publishedweakness classified, att&ck mapped

Affected products

And 15 more affected products. See all after sign-in

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:N

Scored 6.8 by NVD.

How it is reached

  • Attack Vector NetworkExploitable remotely over the network without any special conditions
  • Attack Complexity LowNo special conditions — the attack can be reliably reproduced
  • Privileges Required HighRequires admin or elevated privileges
  • User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

  • Scope ChangedThe exploit can affect other components (e.g. sandbox escape, host compromise from VM)

Impact if exploited

  • Confidentiality NoneNo confidentiality impact
  • Integrity HighTotal loss of integrity — attacker can modify any data in the component
  • Availability NoneNo availability impact

Weaknesses

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Sources

References in the record

And 93 more references. See all after sign-in

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