CVE-2023-42503
Improper Input Validation, Uncontrolled Resource Consumption vulnerability in Apache Commons Compress in TAR parsing.This issue affects Apache Commons Compress: from 1.22 before 1.24.0.
Users are recommended to upgrade to version 1.24.0, which fixes the issue.
A third party can create a malformed TAR file by manipulating file modification times headers, which when parsed with Apache Commons Compress, will cause a denial of service issue via CPU consumption.
In version 1.22 of Apache Commons Compress, support was added for file modification times with higher precision (issue # COMPRESS-612 1). The format for the PAX extended headers carrying this data consists of two numbers separated by a period 2, indicating seconds and subsecond precision (for example “1647221103.5998539”). The impacted fields are “atime”, “ctime”, “mtime” and “LIBARCHIVE.creationtime”. No input validation is performed prior to the parsing of header values.
Parsing of these numbers uses the BigDecimal 3 class from the JDK which has a publicly known algorithmic complexity issue when doing operations on large numbers, causing denial of service (see issue # JDK-6560193 4). A third party can manipulate file time headers in a TAR file by placing a number with a very long fraction (300,000 digits) or a number with exponent notation (such as “9e9999999”) within a file modification time header, and the parsing of files with these headers will take hours instead of seconds, leading to a denial of service via exhaustion of CPU resources. This issue is similar to CVE-2012-2098 5.
Only applications using CompressorStreamFactory class (with auto-detection of file types), TarArchiveInputStream and TarFile classes to parse TAR files are impacted. Since this code was introduced in v1.22, only that version and later versions are impacted.
| Software | From | Fixed in |
|---|---|---|
org.apache.commons / commons-compress
|
1.22 | 1.24.0 |
| apache / commons_compress | 1.22 | 1.24.0 |
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A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
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Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
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