Information disclosure in Citrix NetScaler

1) Information disclosure

EUVDB-ID: #VU9683

Risk: Low

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-17549

CWE-ID: CWE-200 - Information exposure

Exploit availability: No

Description

The vulnerability allows a remote attacker to obtain potentially sensitive information on the target system.

The weakness exists on systems using TLS with client certificates enabled and Diffie-Hellman Ephemeral (DHE) key exchange due to unspecified error. A remote attacker can obtain cleartext traffic from the backend client TLS handshake.

Mitigation

Update to version 10.5 build 67.13, 11.0 build 71.22, 11.1 build 56.19, 12.0 build 53.22 or later.

Vulnerable software versions

Citrix NetScaler: 10.5 - 12.0 Build 53.13

External links

http://support.citrix.com/article/CTX230612

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.