CVE-2019-9555 : What You Need to Know

Sagemcom F@st 5260 routers with firmware version 0.4.39 have a vulnerability in WPA mode that limits the potential pre-shared keys (PSKs) due to insufficient randomness.

Understanding CVE-2019-9555

The CVE-2019-9555 vulnerability affects Sagemcom F@st 5260 routers operating on firmware version 0.4.39 in WPA mode.

What is CVE-2019-9555?

The Sagemcom F@st 5260 routers, when in WPA mode with firmware version 0.4.39, generate pre-shared keys (PSKs) using a combination of known values from a wordlist and a nonce with inadequate randomness, resulting in a limited number of potential PSKs.

The Impact of CVE-2019-9555

The vulnerability restricts the total number of possible PSKs to approximately 1.78 billion, which is considered insufficient for robust security.

Technical Details of CVE-2019-9555

Sagemcom F@st 5260 routers with firmware version 0.4.39 in WPA mode are susceptible to the following:

Vulnerability Description

PSKs are generated from a wordlist of known values and a nonce with insufficient randomness.

Affected Systems and Versions

Product: Sagemcom F@st 5260 routers
Vendor: Sagemcom
Version: 0.4.39

Exploitation Mechanism

Attackers can exploit the limited number of potential PSKs to potentially compromise the security of the network.

Mitigation and Prevention

Steps to address CVE-2019-9555:

Immediate Steps to Take

Disable WPA mode on the affected routers if possible.
Change the default PSK to a strong, randomly generated one.

Long-Term Security Practices

Regularly update router firmware to the latest version.
Implement strong encryption protocols and unique, complex PSKs.

Patching and Updates

Check for firmware updates from Sagemcom and apply them promptly to mitigate the vulnerability.