CVE-2021-36770
Description
A flaw was found in perl-Encode, where the Perl5 Encode module loaded modules within the current directory. This flaw allows an attacker with write access to the current directory of a Perl5 process to inject arbitrary Perl code when this module is loaded, which can be used for a local privilege escalation. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
Statement
Red Hat Enterprise Linux 7 and 8 (including Software Collection) provide older versions of Perl and the Encode library, which are not affected by this flaw.
Mitigation
Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.
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 | 7.8 | 7.8 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | None | N/A |
| User Interaction | None | 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:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity,Confidentiality,Availability,Access Control
Technical Impact: Gain Privileges or Assume Identity; Execute Unauthorized Code or Commands
There is the potential for arbitrary code execution with privileges of the vulnerable program.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
The program could be redirected to the wrong files, potentially triggering a crash or hang when the targeted file is too large or does not have the expected format.
Confidentiality
Technical Impact: Read Files or Directories
The program could send the output of unauthorized files to the attacker.
Acknowledgements
Upstream acknowledges rjbs (perl security team) as the original reporter.
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