How do I Remove RC4 Ciphers in NetScaler?

RC4 stands for RivestCipher 4 is a type of stream cipher i.e it generates streams of bytes one for each byte of the text you want to encrypt. RC4 uses symmetric key encryption algorithm. It is very simple, that once the key stream is generated it is simply XOR-ed with plain text. The key size varies from 64 to 128 bit. This cipher is used in SSL communication and WEP for 802.11.


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RC4 generates a key stream from the secret key and XORs it with plain text to produce the encrypted text. Even though implementation looks simple, RC4 is an encryption algorithm having some vulnerability at initial stages. The first bytes of output reveal information about the key.

NetScaler supports RC4 symmetric key encryption algorithm. There are two ways for removing RC4 from NetScaler. RC4 can be removed from Cipher group or it can be removed from SSL profile.

In order to remove RC4 from your Cipher group to avoid this vulnerability, the following procedure has to be followed.

Note: The below mentioned example is for removing RC4 from Default Cipher group and binding it to a vserver.

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Cisco Wireless LAN Controller CAPWAP Denial of Service Vulnerability

A vulnerability in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol handler of Cisco Wireless LAN Controller (WLC) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.

The vulnerability is due to insufficient validation of CAPWAP packets. An attacker could exploit this vulnerability by sending a malformed CAPWAP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to restart, resulting in a DoS condition.

Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-wlc-capwap-dos-Y2sD9uEw

This advisory is part of the April 2020 Cisco Aironet AP, Mobility Express, and WLC Software Security Advisory Bundled Publication, which includes four Cisco Security Advisories that describe four vulnerabilities. For a complete list of the advisories and links to them, see Cisco Event Response: April 2020 Cisco Aironet AP, Mobility Express and WLC Software Security Advisory Bundled Publication.

Security Impact Rating: High

CVE: CVE-2020-3262

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Wi-Fi Protected Network and Wi-Fi Protected Network 2 Information Disclosure Vulnerability

On February 26th, 2020, researchers Štefan Svorencík and Robert Lipovsky disclosed a vulnerability in the implementation of the wireless egress packet processing of certain Broadcom Wi-Fi chipsets. This vulnerability could allow an unauthenticated, adjacent attacker to decrypt Wi-Fi frames without the knowledge of the Wireless Protected Access (WPA) or Wireless Protected Access 2 (WPA2) Pairwise Temporal Key (PTK) used to secure the Wi-Fi network.

The vulnerability exists because after an affected device handles a disassociation event it could send a limited number of Wi-Fi frames encrypted with a static, weak PTK. An attacker could exploit this vulnerability by acquiring these frames and decrypting them with the static PTK. A successful exploit could allow the attacker to decrypt Wi-Fi frames without the knowledge of the security session establishment used to secure the Wi-Fi network.

Multiple Cisco wireless products are affected by this vulnerability.

Cisco will release software updates that address this vulnerability. There are no workarounds that addresses this vulnerability.

This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200226-wi-fi-info-disclosure

Security Impact Rating: Medium

CVE: CVE-2019-15126

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Offline Cryptographic Attacks Targeting the Wi-Fi Protected Access 2 Protocol

On August 4, 2018, Jens Steube from the Hashcat project published an article introducing a new method to obtain cryptographic information from wireless traffic that can then be used by an attacker to attempt the offline recovery of the preshared key (PSK) used to secure a Wi-Fi network.

Both the Wi-Fi Protected Access (WPA) and the Wi-Fi Protected Access 2 (WPA2) protocols are known to be susceptible to offline cryptographic attacks when a PSK is used as an authentication mechanism. This is not a new vulnerability or a new attack against these protocols. This is a new vector that allows an attacker to obtain the information required to attempt an offline attack against the PSK.

This new method is different from the existing attacks against the PSK because it does not require an attacker to wait for an Extensible Authentication Protocol over LAN (EAPOL) authentication exchange, capture it, and proceed to attempt an offline PSK recovery. This new vector allows an attacker to extract the required information from a single wireless frame transmitted during a roaming event. The following conditions for this capture apply:

  • The frame contains a Robust Security Network-Pairwise Master Key Identification (RSN-PMKID) option
  • The wireless infrastructure is configured to use WPA2 with a PSK mode of authentication
  • The wireless infrastructure supports the Proactive Key Caching (PKC) fast roaming option (PMKID roaming)

The wireless frame can be acquired by passively listening to traffic from the wireless network during the roaming.

It is important to note that this method does not make it easier or faster to recover the PSK for a Wi-Fi network. Instead, it is easier for an attacker to collect the information required to conduct a subsequent offline cryptographic attack. The likelihood of a successful recovery of the PSK is highly dependent on the complexity of the PSK in use.

This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180809-wpa2

Security Impact Rating: Informational

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Cisco Wireless LAN Controller Software Control and Provisioning of Wireless Access Points Protocol Denial of Service Vulnerability

A vulnerability in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol component of Cisco Wireless LAN Controller (WLC) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.
 
The vulnerability is due to improper input validation on fields within CAPWAP Discovery Request packets by the affected device. An attacker could exploit this vulnerability by sending malicious CAPWAP Discovery Request packets to the Cisco WLC Software. A successful exploit could allow the attacker to cause the Cisco WLC Software to disconnect associated access points (APs). While the APs disconnect and reconnect, service will be unavailable for a brief period of time, resulting in a DoS condition.

Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20181017-wlc-capwap-dos

Security Impact Rating: High

CVE: CVE-2018-0443

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Cisco Wireless LAN Controller Software Control and Provisioning of Wireless Access Points Protocol Information Disclosure Vulnerability

A vulnerability in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol component of Cisco Wireless LAN Controller (WLC) Software could allow an unauthenticated, remote attacker to retrieve memory contents, which could lead to the disclosure of confidential information.
 
The vulnerability is due to insufficient condition checks in the part of the code that handles CAPWAP keepalive requests. An attacker could exploit this vulnerability by sending a crafted CAPWAP keepalive packet to a vulnerable Cisco WLC device. A successful exploit could allow the attacker to retrieve the contents of device memory, which could lead to the disclosure of confidential information.

Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20181017-wlc-capwap-memory-leak

Security Impact Rating: High

CVE: CVE-2018-0442

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Error: “Gateway is not Reachable”, Connection Goes Down After the VPN Tunnel is Established

  • Citrix Virtual Adapter is registered as an Ethernet adapter. Starting with Windows 8, the WCMSVC (Windows Connection Manager) disconnects low speed connections because an Ethernet Adapter is seen as more reliable and provides better performance compared to other adapters. That’s the reason, Wi-Fi, 3G/4G adapters get disconnected. But those connections are needed for actual communication with VPN gateway, VPN plugin shows “Gateway is not reachable”.

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    Engineer says Emirate is virtually handing customer data to hackers

    … such as attacker’s access to the wireless networks of a victim, and thus are much less critical than, for example, SQL injection vulnerabilities,” says Kolochenko. “Nonetheless, these risks are material: some cybercrime gangs compromise and backdoor public wi-fi routers to intercept plaintext passwords …

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    Making Spotty WiFi a Bad Memory with the Latitude 7490

    EMC logo


    How many times have you arrived at a meeting on time, only to watch the presenter spend ten minutes troubleshooting a shaky WiFi connection? Or, you’re working from a coffee shop and, after a few minutes of feeling like the “Can you hear me now?” guy with a PC, you realize there’s only one corner with reliable connectivity.

    Dell Latitude 7490 laptop

    WiFi isn’t a nicety for today’s workforce, it’s a necessity. When your connection works, you don’t think about it, but when it doesn’t, work stops.

    Spotty connectivity is not only irritating for workers, it’s also a challenge for IT tasked with broadcasting solid WiFi to the farthest reaches of campus.

    It’s with this rampant problem in mind that Dell is excited to introduce the Dell Latitude 7490 with Intelligent Wireless, featuring the exclusive Active Steering Antenna (ASA) technology, announced at CES 2018.

    How ASA Makes the Most of Weak WiFi

    ASA is designed to give the Latitude 7490 connectivity superpowers. It intelligently detects the location of the strongest wireless signal and reconfigures itself to use that path.

    Think of it like this. Say you’re out to dinner with a friend and that person launches into a story. Will you be able to hear better if you’re facing that person or if your back is turned? That may seem like a silly question, but your PC’s WiFi antenna may very well have its back turned on the best reception spot in the room without your knowing it.

    Effectively, ASA technology makes sure your laptop antenna is “facing” the strongest WiFi signal for the best possible connection.

    How? The antenna chooses from multiple different radio wave patterns to automatically find and lock into the optimal choice for the environment, helping to eliminate dead spots and deliver a more reliable WiFi connection with increased, range and speed.

    ASA Test Performance

    In Dell’s real-world tests, the Latitude 7490 offered substantial throughput improvements over non-ASA-enabled laptops. The most significant improvements were in the locations and orientations where signal reception is on the edge of usability.

    On average, the Latitude 7490 with ASA technology experiences a 40 percent average 11ac throughput enhancement over the same laptop with a passive antenna solution. That translates into fewer dropped connections, successful file transfers and faster email syncs, even on the fringe of the network.

    The Future of Intelligent Wireless

    ASA is an important step in Dell’s journey to improve connectivity for mobile workers. For users, it means less time spent troubleshooting their connection and more time being productive. For IT, it means that last mile of coverage on campus is no longer the last mile.

    Dell is proud to be the first and only to offer ASA technology, exclusively available in certain configurations of the Dell Latitude 7490. There are more connectivity advancements to come as we continue working to solve the real challenges our commercial customers face on a daily basis.

    For the workers relying on a wireless connection to access company files, collaborate and communicate throughout the day (in other words: just about everyone), spotty connectivity is a serious hurdle. Dell is giving those workers tools to be productive and to office anywhere.



    ENCLOSURE:https://blog.dell.com/uploads/2018/02/dell-latitude-7490_964x500.jpg

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