#VU34154 Origin validation error in envoy - CVE-2020-15104
Vulnerability identifier: #VU34154
Vulnerability risk: Medium
CVSSv4.0: 1.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]
CVE-ID:
CWE-ID:
CWE-346
Exploitation vector: Network
Exploit availability: No
Vulnerable software:
envoy
Server applications /
IDS/IPS systems, Firewalls and proxy servers
Vendor: Cloud Native Computing Foundation
Description
The vulnerability allows a remote authenticated user to read and manipulate data.
In Envoy before versions 1.12.6, 1.13.4, 1.14.4, and 1.15.0 when validating TLS certificates, Envoy would incorrectly allow a wildcard DNS Subject Alternative Name apply to multiple subdomains. For example, with a SAN of *.example.com, Envoy would incorrectly allow nested.subdomain.example.com, when it should only allow subdomain.example.com. This defect applies to both validating a client TLS certificate in mTLS, and validating a server TLS certificate for upstream connections. This vulnerability is only applicable to situations where an untrusted entity can obtain a signed wildcard TLS certificate for a domain of which you only intend to trust a subdomain of. For example, if you intend to trust api.mysubdomain.example.com, and an untrusted actor can obtain a signed TLS certificate for *.example.com or *.com. Configurations are vulnerable if they use verify_subject_alt_name in any Envoy version, or if they use match_subject_alt_names in version 1.14 or later. This issue has been fixed in Envoy versions 1.12.6, 1.13.4, 1.14.4, 1.15.0.
Mitigation
Install update from vendor's website.
Vulnerable software versions
envoy: 1.14.0 - 1.14.3
External links
https://github.com/envoyproxy/envoy/security/advisories/GHSA-w5f5-6qhq-hhrg
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
