VDB-246224 · CVE-2023-4398 · GCVE-0-2023-4398

Zyxel ATP/USG FLEX/USG FLEX 50/USG20-VPN/VPN IKE Packet integer overflow

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.
7.5	$5k-$25k	0.00

Summaryinfo

A vulnerability was found in Zyxel ATP, USG FLEX, USG FLEX 50, USG20-VPN and VPN. It has been declared as critical. Affected by this vulnerability is an unknown functionality of the component IKE Packet Handler. Such manipulation leads to integer overflow. This vulnerability is traded as CVE-2023-4398. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Zyxel ATP, USG FLEX, USG FLEX 50, USG20-VPN and VPN (Network Encryption Software). Affected by this issue is some unknown processing of the component IKE Packet Handler. The manipulation with an unknown input leads to a integer overflow vulnerability. Using CWE to declare the problem leads to CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. Impacted is availability. CVE summarizes:

An integer overflow vulnerability in the source code of the QuickSec IPSec toolkit used in the VPN feature of the Zyxel ATP series firmware versions 4.32 through 5.37, USG FLEX series firmware versions 4.50 through 5.37, USG FLEX 50(W) series firmware versions 4.16 through 5.37, USG20(W)-VPN series firmware versions 4.16 through 5.37, and VPN series firmware versions 4.30 through 5.37, could allow an unauthenticated attacker to cause denial-of-service (DoS) conditions on an affected device by sending a crafted IKE packet.

The weakness was shared 11/28/2023. The advisory is shared for download at zyxel.com. This vulnerability is handled as CVE-2023-4398 since 08/17/2023. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 11/28/2023).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Network Encryption Software

Vendor

Zyxel

Name

License

commercial

Website

Vendor: https://www.zyxel.com/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.5

VulDB Base Score: 7.5
VulDB Temp Score: 7.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (Zyxel Corporation): 🔍

CVSSv2info

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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Integer overflow
CWE: CWE-190 / CWE-189
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

08/17/2023 🔍
11/28/2023 +103 days 🔍
11/28/2023 +0 days 🔍
11/28/2023 +0 days 🔍

Sourcesinfo

Vendor: zyxel.com

Advisory: zyxel.com
Status: Confirmed

CVE: CVE-2023-4398 (🔍)
GCVE (CVE): GCVE-0-2023-4398
GCVE (VulDB): GCVE-100-246224

Entryinfo

Created: 11/28/2023 07:51
Changes: 11/28/2023 07:51 (47)
Complete: 🔍
Cache ID: 216::103