Vulnerability Name:

CVE-2018-1000520 (CCN-145617)

Assigned:2018-04-06
Published:2018-04-06
Updated:2020-11-05
Summary: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..
CVSS v3 Severity:7.5 High (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N)
6.6 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:U/RC:R)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): High
Availibility (A): None
5.3 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N)
4.7 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:U/RL:U/RC:R)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): Low
Availibility (A): None
CVSS v2 Severity:5.0 Medium (CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:P/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): Partial
Availibility (A): None
5.0 Medium (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:P/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): Partial
Availibility (A): None
Vulnerability Type:CWE-295
Vulnerability Consequences:Bypass Security
References:Source: MITRE
Type: CNA
CVE-2018-1000520

Source: XF
Type: UNKNOWN
armmbed-cve20181000520-sec-bypass(145617)

Source: CCN
Type: mbedtls GIT Repository
TLS-ECDH-RSA- Ciphersuites Allow ECDSA Signed Certificates #1561

Source: MISC
Type: Issue Tracking, Third Party Advisory
https://github.com/ARMmbed/mbedtls/issues/1561

Source: CCN
Type: WhiteSource Vulnerability Database
CVE-2018-1000520

Vulnerable Configuration:Configuration 1:
  • cpe:/a:arm:mbed_tls:*:*:*:*:*:*:*:* (Version <= 2.7.0)

    • Configuration CCN 1:
  • cpe:/a:arm:mbed_tls:2.7.0:-:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    Oval Definitions
    Definition IDClassTitleLast Modified
    oval:com.ubuntu.disco:def:201810005200000000
    V
    		CVE-2018-1000520 on Ubuntu 19.04 (disco) - low.
    2018-06-26
    oval:com.ubuntu.artful:def:20181000520000
    V
    		CVE-2018-1000520 on Ubuntu 17.10 (artful) - medium.
    2018-06-26
    oval:com.ubuntu.cosmic:def:201810005200000000
    V
    		CVE-2018-1000520 on Ubuntu 18.10 (cosmic) - medium.
    2018-06-26
    oval:com.ubuntu.bionic:def:20181000520000
    V
    		CVE-2018-1000520 on Ubuntu 18.04 LTS (bionic) - medium.
    2018-06-26
    oval:com.ubuntu.bionic:def:201810005200000000
    V
    		CVE-2018-1000520 on Ubuntu 18.04 LTS (bionic) - low.
    2018-06-26
    oval:com.ubuntu.cosmic:def:20181000520000
    V
    		CVE-2018-1000520 on Ubuntu 18.10 (cosmic) - medium.
    2018-06-26
    oval:com.ubuntu.xenial:def:201810005200000000
    V
    		CVE-2018-1000520 on Ubuntu 16.04 LTS (xenial) - low.
    2018-06-26
    oval:com.ubuntu.xenial:def:20181000520000
    V
    		CVE-2018-1000520 on Ubuntu 16.04 LTS (xenial) - medium.
    2018-06-26
    BACK
    arm mbed tls *
    arm mbed tls 2.7.0