CVE-2021-43172

Infinite length chain of RRDP repositories

Severity Score

7.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

NLnet Labs Routinator prior to 0.10.2 happily processes a chain of RRDP repositories of infinite length causing it to never finish a validation run. In RPKI, a CA can choose the RRDP repository it wishes to publish its data in. By continuously generating a new child CA that only consists of another CA using a different RRDP repository, a malicious CA can create a chain of CAs of de-facto infinite length. Routinator prior to version 0.10.2 did not contain a limit on the length of such a chain and will therefore continue to process this chain forever. As a result, the validation run will never finish, leading to Routinator continuing to serve the old data set or, if in the initial validation run directly after starting, never serve any data at all.

NLnet Labs Routinator versiones anteriores a 0.10.2 procesa felizmente una cadena de repositorios RRDP de longitud infinita causando que nunca termine una ejecución de comprobación. En RPKI, una CA puede elegir el repositorio RRDP en el que desea publicar sus datos. Al generar continuamente una nueva CA hija que sólo consiste en otra CA que usa un repositorio RRDP diferente, una CA maliciosa puede crear una cadena de CAs de longitud infinita de facto. Routinator versiones anteriores a 0.10.2, no contenía un límite en la longitud de dicha cadena y por lo tanto continuará procesando esta cadena para siempre. Como resultado, la ejecución de comprobación nunca terminará, conllevando a que Routinator continúe sirviendo el antiguo conjunto de datos o, si en la ejecución de comprobación inicial directamente después de comenzar, nunca sirva ningún dato

*Credits: We would like to thank Koen van Hove for the discovery.

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Attack Vector

Network

Attack Complexity

Low

Authentication

None

Confidentiality

None

Integrity

None

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-11-01 CVE Reserved
2021-11-09 CVE Published
2024-07-25 EPSS Updated
2024-09-16 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-674: Uncontrolled Recursion
CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')

CAPEC

References (1)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://www.nlnetlabs.nl/downloads/routinator/CVE-2021-43172_CVE-2021-43173_CVE-2021-43174.txt	2022-04-25

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Nlnetlabs Search vendor "Nlnetlabs"		Routinator Search vendor "Nlnetlabs" for product "Routinator"				< 0.10.2 Search vendor "Nlnetlabs" for product "Routinator" and version " < 0.10.2"		-		Affected