VDB-232271 · CVE-2023-30362 · Issue 1063

libcoap 4.3.1-103-g52cfd56 pdu coap_send 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.
6.4	$0-$5k	0.00

Summaryinfo

A vulnerability marked as critical has been reported in libcoap 4.3.1-103-g52cfd56. The affected element is the function coap_send of the component pdu Handler. The manipulation leads to buffer overflow. This vulnerability is documented as CVE-2023-30362. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in libcoap 4.3.1-103-g52cfd56. It has been rated as critical. This issue affects the function coap_send of the component pdu Handler. The manipulation with an unknown input leads to a buffer overflow vulnerability. Using CWE to declare the problem leads to 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. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Buffer Overflow vulnerability in coap_send function in libcoap library 4.3.1-103-g52cfd56 fixed in 4.3.1-120-ge242200 allows attackers to obtain sensitive information via malformed pdu.

The weakness was released 06/23/2023 as 1063. It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2023-30362 since 04/07/2023. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 4.3.1-120-ge242200 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 EUVD (EUVD-2023-34783). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Name

libcoap

Version

4.3.1-103-g52cfd56

CPE 2.3info

🔍

CPE 2.2info

🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.4

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

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

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: libcoap 4.3.1-120-ge242200
Patch: github.com

Timelineinfo

04/07/2023 🔍
06/23/2023 +77 days 🔍
06/23/2023 +0 days 🔍
12/22/2025 +913 days 🔍

Sourcesinfo

Advisory: 1063
Status: Confirmed

CVE: CVE-2023-30362 (🔍)
GCVE (CVE): GCVE-0-2023-30362
GCVE (VulDB): GCVE-100-232271
EUVD: 🔍

Entryinfo

Created: 06/23/2023 15:07
Updated: 12/22/2025 08:56
Changes: 06/23/2023 15:07 (42), 07/18/2023 07:58 (11), 12/22/2025 08:56 (16)
Complete: 🔍
Cache ID: 216::103