L4 traffic bypass via L7 deny fail-open
Published Jul 17, 2021 · Updated Aug 4, 2024
Access control bypass in HashiCorp Consul 1.9.0 through 1.10.0 allows remote attackers to pass denied L4 traffic via Consul Connect. The xDS RBAC intention logic cancels a single L7 deny action under a default-deny policy, removing the effective permission and generating an allow path for the underlying L4 connection. Exploitation requires the specific default-deny and single application-aware L7 deny configuration, which the vendor describes as uncommon; the consequence is unauthorized service connectivity rather than data disclosure or service interruption.
Summary
What happened
Access control bypass in HashiCorp Consul 1.9.0 through 1.10.0 allows remote attackers to pass denied L4 traffic via Consul Connect. The xDS RBAC intention logic cancels a single L7 deny action under a default-deny policy, removing the effective permission and generating an allow path for the underlying L4 connection. Exploitation requires the specific default-deny and single application-aware L7 deny configuration, which the vendor describes as uncommon; the consequence is unauthorized service connectivity rather than data disclosure or service interruption.
The record
- CVE
- CVE-2021-36213
- Published
- Jul 17, 2021
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 17, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo