Vulnerability in Arm Mbed TLS

CVE-2018-1000520

ARM mbedTLS version 2.7.0 and earlier contains a Ciphersuite Allows Incorrectly Signed Certificates vulnerability in mbedtls_ssl_get_verify_result() that can result in ECDSA-signed certificates are accepted, when only RSA-signed ones should be.. This attack appear to be exploitable via Peers negotiate a TLS-ECDH-RSA-* ciphersuite. Any of the peers can then provide an ECDSA-signed certificate, when only an RSA-signed one should be accepted..

Vulnerability class: Improper Certificate Validation

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.007 (52.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 52.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2018-1000520: held from 0.007 to 0.007.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2018-1000520?
CVE-2018-1000520 is a high-severity vulnerability in Arm Mbed TLS, classified under Improper Certificate Validation. CVSS score: 7.5/10. Published 2018-06-26.
How severe is CVE-2018-1000520?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2018-1000520 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.