CVE-2019-14866
Description
It was discovered cpio does not properly validate input files when generating TAR archives. When cpio is used to create TAR archives from paths an attacker can write to, the resulting archive may contain files with permissions the attacker did not have or in paths he did not have access to. Extracting those archives from a high-privilege user without carefully reviewing them may lead to the compromise of the system.
Mitigation
TAR archives should be inspected before being extracted and the extraction should be performed with the `tar` command or `--no-absolute-filenames` option if done with `cpio`. Moreover, it should be performed by a low-privilege user whenever possible, to prevent extraction of files that could compromise the system.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.7 | 7.3 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | High | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | Required | Required | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.0/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
Red Hat CVSS v3 Score Explanation
Attack Complexity (AC) set to High (H) as the conditions to have an Impact on Confidentiality, Integrity and Availability of High are quite convoluted and are not under the attacker's control.
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
An attacker could provide unexpected values and cause a program crash or arbitrary control of resource allocation, leading to excessive consumption of resources such as memory and CPU.
Confidentiality
Technical Impact: Read Memory; Read Files or Directories
An attacker could read confidential data if they are able to control resource references.
Integrity,Confidentiality,Availability
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
An attacker could use malicious input to modify data or possibly alter control flow in unexpected ways, including arbitrary command execution.
Acknowledgements
Red Hat would like to thank Thomas Habets for reporting this issue.
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