Comcast’s Xfinity customer data exposed after CitrixBleed attack
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2023-4966 | Info-Disclosure Buffer Overflow (CitrixBleed) in Citrix NetScaler ADC/Gateway Citrix NetScaler ADC and NetScaler Gateway appliances contain a buffer overflow (CWE-119) that leaks sensitive information from device memory when the appliance is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, or RDP Proxy) or as an AAA virtual server. A remote attacker who can reach such a configuration can trigger the overflow and read memory contents, harvesting sensitive data such as session tokens (a technique that enables session hijacking which can bypass multi-factor authentication). Any organization running an affected NetScaler ADC or Gateway appliance in these configurations is exposed, with appliances deployed as VPN or access gateways being the primary concern. Exploitation is confirmed in the wild: the flaw was added to CISA's KEV catalog on 2023-10-18 with known ransomware use and a 100% EPSS exploitation probability, although no public proof-of-concept is known at this time. Because tokens stolen from memory can remain valid even after patching, responders must terminate all active and persistent sessions as part of remediation. Do: Upgrade affected appliances to the patched builds cited in Citrix's advisory, then immediately kill all active and persistent ICA/AAA sessions per the vendor instructions, since patching alone does not invalidate session tokens attackers may have already stolen. If patching is not immediately possible, discontinue use of the affected Gateway/AAA configurations as CISA directs. Given known ransomware abuse, also hunt for signs of exploitation such as logins from unexpected sources, anomalous session reuse, or suspicious mailbox changes, and reset credentials for potentially exposed accounts. | 7.5 | 100% | KEV ransomware |
| masshundreds of thousands of internet-exposed NetScaler ADC/Gateway appliances (public internet scan counts), plus an unknown number of VPN-only or internal… |
Full article390 words · extracted from securityaffairs.com · click to collapse
Pierluigi Paganini
December 19, 2023
Comcast’s Xfinity discloses a data breach after a cyber attack hit the company by exploiting the CitrixBleed vulnerability.
Comcast’s Xfinity is notifying its customers about the compromise of their data in a cyberattack that involved the exploitation of the CitrixBleed flaw.
CitrixBleed is a critical vulnerability, tracked as CVE-2023-4966, in Citrix NetScaler ADC (Application Delivery Controller) software. An unauthorized attacker can exploit the flaw to gain access to sensitive data and systems. The vulnerability was discovered by security researchers at Positive Technologies and disclosed to Citrix in October 10, 2023. Citrix released a patch for the vulnerability on November 15, 2023
Threat actors exploited this vulnerability to hijack existing authenticated sessions and bypass multifactor authentication or other strong authentication requirements. The researchers warn that these sessions may persist after the update to mitigate CVE-2023-4966 has been deployed.
Security firm Mandiant observed threat actors hijacking sessions where session data was stolen before the patch deployment and subsequently used by the threat actor.
Xfinity is a brand of Comcast Cable Communications, LLC, which is a subsidiary of Comcast Corporation. Xfinity offers a variety of services, including cable television, internet, telephone, and home security. It is a major provider of broadband internet and cable TV services in the United States.
The company addressed the issue shortly after Citrix disclosed the issue on October, however, they subsequently discovered that before mitigation, there was unauthorized access to some of it internal systems. Threat actors exploited the flaw between October 16 and October 19, 2023.
The company notified law enforcement and launched an investigation into the incident.
“On November 16, 2023, it was determined that information was likely acquired.” reads the notice of a security incident. “On December 6, 2023, we concluded that the information included usernames and hashed passwords. For some customers, other information was also included, such as names, contact information, last four digits of social security numbers, dates of birth and/or secret questions and answers. However, our data analysis is continuing, and we will provide additional notices as appropriate.”
The company found that the exposed customer data varies for each customer, including usernames and hashed passwords.
The company prompted customers to reset their passwords and recommended they enable multi-factor authentication.
Follow me on Twitter: @securityaffairs and Facebook and Mastodon
(SecurityAffairs – hacking, CitrixBleed)
Text extracted automatically; images, tables and formatting may be missing. Original: https://securityaffairs.com/156147/data-breach/comcasts-xfinity-customer-data-exposed-after-citrixbleed-attack.html