C-Blosc2 up to 2.17.0 compress_chunk_fuzzer buffer overflow

HistoryDiffrelatejsonxmlCTI

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.
5.2	$0-$5k	0.00

Summaryinfo

A vulnerability has been found in C-Blosc2 up to 2.17.0 and classified as critical. Impacted is the function compress_chunk_fuzzer. Performing a manipulation results in buffer overflow. This vulnerability is known as CVE-2025-29476. Furthermore, an exploit is available.

Detailsinfo

A vulnerability was found in C-Blosc2 up to 2.17.0. It has been classified as critical. This affects the function compress_chunk_fuzzer. 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:

Buffer Overflow vulnerability in compress_chunk_fuzzer with oss-fuzz on commit 16450518afddcb3139de627157208e49bfef6987 in c-blosc2 v.2.17.0 and before.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2025-29476 since 03/11/2025. The exploitability is told to be easy. Technical details and a public exploit are known.

The exploit is shared for download at github.com. It is declared as proof-of-concept.

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

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2025-9764). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Name

C-Blosc2

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.5
VulDB Meta Temp Score: 5.2

VulDB Base Score: 5.5
VulDB Temp Score: 5.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

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: Partially

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Download: 🔍

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

03/11/2025 🔍
04/04/2025 +23 days 🔍
04/04/2025 +0 days 🔍
06/08/2025 +65 days 🔍

Sourcesinfo

Advisory: 656
Status: Confirmed

CVE: CVE-2025-29476 (🔍)
GCVE (CVE): GCVE-0-2025-29476
GCVE (VulDB): GCVE-100-303495
EUVD: 🔍
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 04/04/2025 22:05
Updated: 06/08/2025 16:58
Changes: 04/04/2025 22:05 (56), 06/08/2025 16:58 (1)
Complete: 🔍
Cache ID: 216::103