USN-2672-1: NSS vulnerabilities
Karthikeyan Bhargavan discovered that NSS incorrectly handled state transitions for the TLS state machine. If a remote attacker were able to perform a machine-in-the-middle attack, this flaw could be exploited to skip the ServerKeyExchange message and remove the forward-secrecy property. (CVE-2015-2721) Watson Ladd discovered that NSS incorrectly handled Elliptical Curve Cryptography (ECC) multiplication. A remote attacker could possibly use this issue to spoof ECDSA signatures. (CVE-2015-2730) As a security improvement, this update modifies NSS behaviour to reject DH key sizes below 768 bits, preventing a possible downgrade attack. This update also refreshes the NSS package to version 3.19.2 which includes the latest CA certificate bundle.
Affected Software
Event History
Frequently Asked Questions
What is the vulnerability ID?
The vulnerability ID is USN-2672-1.
What was discovered about NSS?
NSS incorrectly handled state transitions for the TLS state machine.
What is the impact of this vulnerability?
An attacker could exploit this vulnerability to perform a man-in-the-middle attack and remove the forward-secrecy property.
How can this vulnerability be exploited?
By performing a machine-in-the-middle attack, an attacker can exploit this vulnerability.
Where can I find more information about this vulnerability?
You can find more information about this vulnerability at the following references: [CVE-2015-2721](https://ubuntu.com/security/CVE-2015-2721), [CVE-2015-2730](https://ubuntu.com/security/CVE-2015-2730), [USN-2673-1](https://ubuntu.com/security/notices/USN-2673-1)