CVE-2023-50977
Description
A flaw was found In gnome-shell. The GNOME Network Manager and GNOME Shell Portal Helper connectivity checks send DNS checks that, if intercepted, may be used to launch a GNOME Captive Portal in a WebKitGTK browser and load arbitrary HTML and Javascript code.
Statement
This vulnerability is classified as moderate severity rather than high because it requires a specific and controlled environment to be exploited effectively. The attacker needs to perform DNS hijacking within the same local network, which limits the scope of potential targets. Additionally, the exploit depends on the GNOME Captive Portal automatically opening a WebKitGTK browser, which, while a default behavior, may not be universally applicable across all GNOME configurations. Furthermore, modern web browsers use sandboxing as a mechanism to contain malicious activity, significantly reducing the potential impact of the exploit. This sandboxing mitigates the risk of the attack affecting other parts of the system, thus lowering the severity of this flaw to moderate. The exploitation vector, while technically feasible, involves multiple steps that reduce the likelihood of widespread, automated attacks. Thus, the impact, while serious, is confined to scenarios with network control and specific GNOME settings, justifying its moderate severity classification.
Mitigation
Mitigation for this issue is either not available or the currently available options don't 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 | 7.5 | N/A | N/A |
| Attack Vector | Adjacent Network | N/A | N/A |
| Attack Complexity | High | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | High | N/A | N/A |
| Integrity Impact | High | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
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.
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