Security restrictions bypass in mbed TLS - CVE-2017-18187

 

Security restrictions bypass in mbed TLS - CVE-2017-18187

Published: March 15, 2018


Vulnerability identifier: #VU11120
CSH Severity: Low
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2017-18187
CWE-ID: CWE-190
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to bypass security restrictions on the target system.

The weakness exists due to integer overflow in PSK identity parsing in the ssl_parse_client_psk_identity() function in library/ssl_srv.c. A remote attacker can trigger memory corruption and bypass bounds-check.

Affected software

mbed TLS
Debian Linux
Gentoo Linux
Fedora
mbedtls (Ubuntu package)
mbedtls (Alpine package)
mbedtls

How to mitigate CVE-2017-18187

Install update from vendor's website.

mbedtls (Ubuntu package) - update to 2.2.1-2ubuntu0.3
mbedtls (Alpine package) - update to 2.7.0-r0
mbedtls - addressed in versions 2.7.0-1.el6, 2.7.0-1.el7, 2.7.0-1.fc26, 2.7.0-1.fc27

External References

Related Security Bulletins