VDB-254295 · CVE-2023-6936 · Nessus 212849

wolfSSL up to 5.6.5 Callback buffer 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.
7.1	$0-$5k	0.00

Summaryinfo

A vulnerability classified as critical has been found in wolfSSL up to 5.6.5. This affects an unknown function of the component Callback Handler. Performing a manipulation results in buffer overflow. This vulnerability is known as CVE-2023-6936. Remote exploitation of the attack is possible. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in wolfSSL up to 5.6.5. This affects some unknown processing of the component Callback Handler. The manipulation with an unknown input leads to a buffer overflow vulnerability. CWE is classifying the issue as CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In wolfSSL prior to 5.6.6, if callback functions are enabled (via the WOLFSSL_CALLBACKS flag), then a malicious TLS client or network attacker can trigger a buffer over-read on the heap of 5 bytes (WOLFSSL_CALLBACKS is only intended for debugging).

The weakness was published 02/21/2024 by Lucca Hirschi. It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2023-6936 since 12/18/2023. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 212849 (CBL Mariner 2.0 Security Update: mariadb (CVE-2023-6936)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.6.6 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (212849). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Name

wolfSSL

Version

License

open-source

Website

Product: https://github.com/wolfSSL/wolfssl/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.2
VulDB Meta Temp Score: 7.1

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.1
NVD Vector: 🔍

CNA Base Score: 5.3
CNA Vector (wolfSSL Inc.): 🔍

CVSSv2info

AV	AC	Au	C	I	A
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Buffer overflow
CWE: CWE-120 / CWE-119
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

Nessus ID: 212849
Nessus Name: CBL Mariner 2.0 Security Update: mariadb (CVE-2023-6936)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: wolfSSL 5.6.6
Patch: github.com

Timelineinfo

12/18/2023 🔍
02/21/2024 +65 days 🔍
02/21/2024 +0 days 🔍
02/13/2025 +358 days 🔍

Sourcesinfo

Product: github.com

Advisory: github.com
Researcher: Lucca Hirschi
Status: Confirmed

CVE: CVE-2023-6936 (🔍)
GCVE (CVE): GCVE-0-2023-6936
GCVE (VulDB): GCVE-100-254295

Entryinfo

Created: 02/21/2024 09:20
Updated: 02/13/2025 02:18
Changes: 02/21/2024 09:20 (50), 03/09/2024 00:38 (1), 12/14/2024 04:27 (17), 02/13/2025 02:18 (12)
Complete: 🔍
Cache ID: 216::103