// For flags

CVE-2022-30699

Novel "ghost domain names" attack by updating almost expired delegation information

Severity Score

6.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

NLnet Labs Unbound, up to and including version 1.16.1, is vulnerable to a novel type of the "ghost domain names" attack. The vulnerability works by targeting an Unbound instance. Unbound is queried for a rogue domain name when the cached delegation information is about to expire. The rogue nameserver delays the response so that the cached delegation information is expired. Upon receiving the delayed answer containing the delegation information, Unbound overwrites the now expired entries. This action can be repeated when the delegation information is about to expire making the rogue delegation information ever-updating. From version 1.16.2 on, Unbound stores the start time for a query and uses that to decide if the cached delegation information can be overwritten.

NLnet Labs Unbound, versiones hasta 1.16.1 incluyéndola, es vulnerable a un nuevo tipo de ataque de "ghost domain names". La vulnerabilidad funciona apuntando a una instancia de Unbound. Unbound es consultado por un nombre de dominio falso cuando la información de delegación en caché está a punto de expirar. El servidor de nombres falso retrasa la respuesta para que la información de delegación almacenada en la caché caduque. Al recibir la respuesta retrasada que contiene la información de la delegación, Unbound sobrescribe las entradas ya caducadas. Esta acción puede repetirse cuando la información de la delegación está a punto de caducar, haciendo que la información de la delegación falsa sea actualizada constantemente. A partir de la versión 1.16.2, Unbound almacena la hora de inicio de una consulta y la usa para decidir si la información de delegación almacenada en caché puede sobrescribirse

A flaw was found in Unbound, which is vulnerable to a novel type of "ghost domain names" attack. The vulnerability works by targeting an Unbound instance. Unbound is queried for a subdomain of a rogue domain name. The rogue nameserver returns delegation information for the subdomain that updates Unbound's delegation cache. This action can be repeated before the expiry of the delegation information by querying Unbound for a second-level subdomain in which the rogue nameserver provides new delegation information. Since Unbound is a child-centric resolver, the ever-updating child delegation information can keep a rogue domain name resolvable long after revocation.

*Credits: We would like to thank Xiang Li from the Network and Information Security Lab of Tsinghua University for discovering and disclosing the vulnerability.
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2022-05-13 CVE Reserved
  • 2022-08-01 CVE Published
  • 2024-06-17 EPSS Updated
  • 2024-09-16 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-613: Insufficient Session Expiration
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Nlnetlabs
Search vendor "Nlnetlabs"
Unbound
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< 1.16.2
Search vendor "Nlnetlabs" for product "Unbound" and version " < 1.16.2"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
Fedora
Search vendor "Fedoraproject" for product "Fedora"
35
Search vendor "Fedoraproject" for product "Fedora" and version "35"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
Fedora
Search vendor "Fedoraproject" for product "Fedora"
36
Search vendor "Fedoraproject" for product "Fedora" and version "36"
-
Affected