Citrix NetScaler ADC/NetScaler Gateway OpenID openid-configuration CitrixBleed memory corruption

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
8.2$0-$5k2.61

Summaryinfo

A vulnerability identified as very critical has been detected in Citrix NetScaler ADC and NetScaler Gateway. This affects the function ns_aaa_oauth_send_openid_config/ns_aaa_oauthrp_send_openid_config of the file /oauth/idp/.well-known/openid-configuration of the component OpenID Handler. This manipulation causes memory corruption. This vulnerability is registered as CVE-2023-4966. Remote exploitation of the attack is possible. Furthermore, an exploit is available. This vulnerability has a historic impact because of its background and how it was received. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as very critical was found in Citrix NetScaler ADC and NetScaler Gateway (Network Management Software) (affected version not known). Affected by this vulnerability is the function ns_aaa_oauth_send_openid_config/ns_aaa_oauthrp_send_openid_config of the file /oauth/idp/.well-known/openid-configuration of the component OpenID Handler. The manipulation with an unknown input leads to a memory corruption vulnerability. The CWE definition for the vulnerability is CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Sensitive information disclosure in NetScaler ADC and NetScaler Gateway when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA  virtual server.

The weakness was published 10/10/2023 as CTX579459. The advisory is shared at support.citrix.com. This vulnerability is known as CVE-2023-4966 since 09/14/2023. Technical details and also a public exploit are known. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/31/2026). Due to its background and reception, this vulnerability has a historic impact.

It is possible to download the exploit at github.com. It is declared as attacked. We expect the 0-day to have been worth approximately $25k-$100k. The CISA Known Exploited Vulnerabilities Catalog lists this issue since 10/18/2023 with a due date of 11/08/2023:

Apply mitigations and kill all active and persistent sessions per vendor instructions [https://www.netscaler.com/blog/news/cve-2023-4966-critical-security-update-now-available-for-netscaler-adc-and-netscaler-gateway/] OR discontinue use of the product if

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Zero-Day.cz (829). Additional details are provided at assetnote.io. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

Video

Open Video | Show More Videos

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.3
VulDB Meta Temp Score: 8.2

VulDB Base Score: 8.1
VulDB Temp Score: 7.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CNA Base Score: 9.4
CNA Vector (Citrix Systems, Inc.): 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory corruption
CWE: CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Attacked
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

KEV Added: 🔍
KEV Due: 🔍
KEV Remediation: 🔍
KEV Ransomware: 🔍
KEV Notice: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Zero-Day.cz: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Timelineinfo

09/14/2023 🔍
10/10/2023 +26 days 🔍
10/10/2023 +0 days 🔍
07/31/2026 +1025 days 🔍

Sourcesinfo

Vendor: citrix.com

Advisory: CTX579459
Status: Confirmed

CVE: CVE-2023-4966 (🔍)
GCVE (CVE): GCVE-0-2023-4966
GCVE (VulDB): GCVE-100-241705
scip Labs: https://www.scip.ch/en/?labs.20161013
Misc.: 🔍

Entryinfo

Created: 10/10/2023 16:46
Updated: 07/31/2026 06:40
Changes: 10/10/2023 16:46 (49), 10/27/2023 08:23 (9), 10/28/2023 14:35 (11), 11/15/2023 15:50 (10), 11/16/2023 11:37 (4), 04/29/2024 19:17 (23), 06/06/2024 02:22 (2), 06/17/2024 16:39 (2), 09/09/2024 22:30 (1), 07/31/2026 06:40 (1)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you want to use VulDB in your project?

Use the official API to access entries easily!