CVE-2021-37712
Description
A flaw was found in the npm package "tar" (aka node-tar). Extracting tar files that contain two directories and a symlink with names containing Unicode values that normalize to the same value on Windows systems made it possible to bypass node-tar symlink checks on directories. This allows an untrusted tar file to extract and overwrite files into an arbitrary location. The highest threat from this vulnerability is to integrity and system availability.
Statement
Red Hat Enterprise Linux version 8 and Red Hat Software Collection both embed node-tar in the npm command. However, npm explicitly prevents the extraction of symlink via a filter. npm might still be affected via node-gyp, if the attacker is able to control the target URL.
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 | 8.1 | 8.6 | 8.2 |
| Attack Vector | Network | Local | Local |
| Attack Complexity | Low | Low | Low |
| Privileges Required | None | None | None |
| User Interaction | Required | Required | Required |
| Scope | Unchanged | Changed | Changed |
| Confidentiality | None | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | High | High | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
Understanding the Weakness (CWE)
Confidentiality,Integrity,Access Control
Technical Impact: Read Files or Directories; Modify Files or Directories; Bypass Protection Mechanism
An attacker may be able to traverse the file system to unintended locations and read or overwrite the contents of unexpected files. If the files are used for a security mechanism then an attacker may be able to bypass the mechanism.
Other
Technical Impact: Execute Unauthorized Code or Commands
Windows simple shortcuts, sometimes referred to as soft links, can be exploited remotely since a ".LNK" file can be uploaded like a normal file. This can enable remote execution.
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