CVE-2023-27533
Description
From CVE.org
A vulnerability in input validation exists in curl <8.0 during communication using the TELNET protocol may allow an attacker to pass on maliciously crafted user name and "telnet options" during server negotiation. The lack of proper input scrubbing allows an attacker to send content or perform option negotiation without the application's intent. This vulnerability could be exploited if an application allows user input, thereby enabling attackers to execute arbitrary code on the system.
Statement
While this vulnerability exists in Curl, the potential impact is to a different component. The overall impact is limited to the telnet component. On its own this flaw has a limited to negligible effect on integrity of the entire system, therefore it has been rated as having a Low security impact. This is in alignment with upstream’s impact assessment, their advisory is linked in external references.
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 | 4.3 | 8.8 | 9.8 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | None | None | None |
| User Interaction | Required | Required | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | High | High |
| Integrity Impact | Low | High | High |
| Availability Impact | None | High | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Red Hat CVSS v3 Score Explanation
This vulnerability allows the bypass of some input filtering (so Integrity impact is rated Low). It does not enable access to additional information (so the Confidentiality impact is rated None) nor can it modify the operations of Curl (so Availability impact is rated None). From the perspective of the operating system or an even larger product using the OS, without the presence of additional vulnerabilities in telnet, the impact of this flaw simply would not be noticed.
Understanding the Weakness (CWE)
Integrity,Confidentiality,Availability
Technical Impact: Modify Application Data; Execute Unauthorized Code or Commands
Acknowledgements
Red Hat would like to thank Daniel Stenberg and Harry Sintonen for reporting this issue.
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