Vulnerability identifier: #VU42731

Vulnerability risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-15136

CWE-ID: CWE-287

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
etcd
Server applications / Database software

Vendor: CoreOS

Description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to gateway TLS authentication is only applied to endpoints detected in DNS SRV records. When starting a gateway, TLS authentication will only be attempted on endpoints identified in DNS SRV records for a given domain, which occurs in the discoverEndpoints function. No authentication is performed against endpoints provided in the --endpoints flag.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

etcd: 3.3.0 - 3.4.9

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External links
http://github.com/etcd-io/etcd/blob/master/Documentation/op-guide/gateway.md
http://github.com/etcd-io/etcd/security/advisories/GHSA-wr2v-9rpq-c35q

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.