CVE-2021-43173

Description

In NLnet Labs Routinator prior to 0.10.2, a validation run can be delayed significantly by an RRDP repository by not answering but slowly drip-feeding bytes to keep the connection alive. This can be used to effectively stall validation. While Routinator has a configurable time-out value for RRDP connections, this time-out was only applied to individual read or write operations rather than the complete request. Thus, if an RRDP repository sends a little bit of data before that time-out expired, it can continuously extend the time it takes for the request to finish. Since validation will only continue once the update of an RRDP repository has concluded, this delay will cause validation to stall, 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.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
cfrpki	25.10 questing	Not in release
	25.04 plucky	Not in release
	24.10 oracular	Not in release
	24.04 LTS noble	Not in release
	23.10 mantic	Not affected
	23.04 lunar	Not affected
	22.10 kinetic	Not affected
	22.04 LTS jammy	Not affected
	21.10 impish	Ignored end of life
	16.04 LTS xenial	Ignored end of standard support
	14.04 LTS trusty	Ignored end of standard support
fort-validator	25.10 questing	Not affected
	25.04 plucky	Not affected
	24.10 oracular	Ignored end of life
	24.04 LTS noble	Not affected
	23.10 mantic	Ignored end of life
	23.04 lunar	Ignored end of life
	22.10 kinetic	Ignored end of life
	22.04 LTS jammy	Not affected
	21.10 impish	Ignored end of life
	20.04 LTS focal	Vulnerable
	16.04 LTS xenial	Ignored end of standard support
	14.04 LTS trusty	Ignored end of standard support
routinator	16.04 LTS xenial	Ignored end of standard support
routinator	14.04 LTS trusty	Ignored end of standard support
rpki-client	25.10 questing	Not affected
	25.04 plucky	Not affected
	24.10 oracular	Not affected
	24.04 LTS noble	Not affected
	23.10 mantic	Not affected
	23.04 lunar	Not affected
	22.10 kinetic	Not affected
	22.04 LTS jammy	Not affected
	21.10 impish	Ignored end of life
	16.04 LTS xenial	Ignored end of standard support
	14.04 LTS trusty	Ignored end of standard support

Notes

ej7367

Although the CVE description only mentions Routinator, fort-validator before v1.5.3 is also vulnerable to this type of attack.

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
fort-validator	Upstream: a28c2cc

Severity score breakdown

Parameter	Value
Base score	7.5 · High
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	High
Availability impact	None
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N