CyberSecBulletin
CVE-2022-1053NVD status: Modified

Keylime does not enforce that the agent registrar data is the same when the tenant uses it for…

Published Updated By the CyberSecBulletin desk

CVE-2022-1053 is a critical-severity improper input validation vulnerability in keylime, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected keylime versions: Affects keylime v6.4.0 and prior, Fixed in – v6.4.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.48% chance of exploitation within 30 days, higher than 74% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of keylime you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
KeylimekeylimeAffects keylime v6.4.0 and prior, Fixed in – v6.4.0Not stated
Fedora ProjectFedora34; 35; 36Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.19.1CriticalNVD
CVSS 2.06.4MediumNVD

Official description

Keylime does not enforce that the agent registrar data is the same when the tenant uses it for validation of the EK and identity quote and the verifier for validating the integrity quote. This allows an attacker to use one AK, EK pair from a real TPM to pass EK validation and give the verifier an AK of a software TPM. A successful attack breaks the entire chain of trust because a not validated AK is used by the verifier. This issue is worse if the validation happens first and then the agent gets added to the verifier because the timing is easier and the verifier does not validate the regcount entry being equal to 1,

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How developers prevent this class of flaw

  • Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build recognizers for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses.
  • Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
  • Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.

More Improper Input Validation vulnerabilities (CWE-20)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in keylime

All keylime vulnerabilities

Recent Improper Input Validation vulnerabilities

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