Hi We have switch c3850/ver 03.03.01.SE. Now some insecurity message (Please see the below) is sent to us from tenable.
The device has the below two commands. Are these two commands is the reason for the insecurity? Thank you
ip ssh server algorithm encryption aes128-ctr aes192-ctr aes256-ctr
ip ssh client algorithm encryption aes128-ctr aes192-ctr aes256-ctr
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message is from tenable:
"The remote service accepts connections encrypted using SSL 2.0 and/or
SSL 3.0. These versions of SSL are affected by several cryptographic
flaws, including:
- An insecure padding scheme with CBC ciphers.
- Insecure session renegotiation and resumption schemes.
An attacker can exploit these flaws to conduct man-in-the-middle
attacks or to decrypt communications between the affected service and
clients.
Although SSL/TLS has a secure means for choosing the highest supported
version of the protocol (so that these versions will be used only if
the client or server support nothing better), many web browsers
implement this in an unsafe way that allows an attacker to downgrade
a connection (such as in POODLE). Therefore, it is recommended that
these protocols be disabled entirely.
NIST has determined that SSL 3.0 is no longer acceptable for secure
communications. As of the date of enforcement found in PCI DSS v3.1,
any version of SSL will not meet the PCI SSC's definition of 'strong
cryptography'."
