CVE-2021-20193
Description
A flaw was found in the src/list.c of tar. This flaw allows an attacker who can submit a crafted input file to tar to cause uncontrolled consumption of memory. The highest threat from this vulnerability is to system availability.
Statement
The vulnerability in GNU Tar is rated as moderate severity because, while it results in a denial of service through memory leaks, its exploitation is constrained to the application's operational context without impacting the broader system integrity or security. The leak occurs in the read_header() function, where memory allocated for handling tar entries is not properly released, leading to resource exhaustion. However, this vulnerability does not facilitate arbitrary code execution, privilege escalation, or data corruption, which are characteristic of higher-severity vulnerabilities. Furthermore, the memory leak is contingent upon user interaction, as it requires the extraction of maliciously crafted tar files, thereby limiting its potential for widespread exploitation.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 3.3 | 3.3 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | Required | Required | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | Low | Low | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
NVD: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
Red Hat CVSS v3 Score Explanation
The Availability Impact of the GNU Tar memory leak is rated as low due to the leak occurs in the read_header() function, causing increased memory consumption only within the tar process, without affecting other system applications. Exploitation requires user interaction, as it is triggered by extracting specially crafted tar files, limiting its potential for widespread disruption.
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (Other); DoS: Resource Consumption (Memory); DoS: Resource Consumption (CPU)
An attacker that can influence the allocation of resources that are not properly released could deplete the available resource pool and prevent all other processes from accessing the same type of resource. Frequently-affected resources include memory, CPU, disk space, power or battery, etc.
Frequently Asked Questions
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