CVE-2019-25777
Description
A flaw was found in perl-yaml. This vulnerability can lead to arbitrary code execution because the parser fails to restrict package variable modifications specified in YAML documents. An attacker capable of submitting crafted YAML input can overwrite internal configuration settings to enable code loading, allowing them to execute arbitrary Perl code within the running process.
Statement
This vulnerability is rated as Important severity because successful exploitation allows an attacker to achieve arbitrary code execution within the context of the running Perl application, potentially compromising the host system. Although embedded code evaluation is disabled by default in Red Hat Enterprise Linux packages, an attacker supplying malicious serialized YAML data can bypass these safeguards by modifying package-level variables and runtime configurations in memory. Exploitation requires the target application to accept untrusted inputs and process them across multiple deserialization calls within a persistent execution context.
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 | 8.1 | N/A | 7.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | Low |
| Integrity Impact | High | N/A | Low |
| Availability Impact | High | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
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