CVE-2023-4504
Description
A vulnerability was found in CUPS and libppd, where a failure to validate the length provided in an attacker-crafted PPD PostScript document can lead to a heap-based buffer overflow, causing a denial of service or, in some cases, execute arbitrary code, depending on how the application processes untrusted PPD files.
Statement
This vulnerability is rated as moderate because a heap-based buffer overflow in CUPS and libppd, caused by improper length validation in attacker-crafted PPD PostScript documents, could lead to application crashes or potential code execution, successful exploitation depends on specific conditions, such as the application's processing of untrusted PPD files, limiting the overall impact in most cases.
Mitigation
For a successful attack, the victim had to install a PPD file (driver) that contains the crafted PS sequence, which triggers the issue. It is not recommended to install drivers from unreliable sources.
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 | 7 | 7 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | High | High | High |
| Privileges Required | None | None | None |
| User Interaction | Required | Required | Required |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | High | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Red Hat CVSS v3 Score Explanation
The effectiveness of the attack hinges on eluding or bypassing the existing security measures designed to impede it. The attacker needs alternative methods to navigate through the established security protocols. Additionally, for a successful attack, the victim must install a PPD file (driver) containing a carefully crafted PS sequence that triggers the issue. It is strongly advised against installing drivers from untrustworthy sources.
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop.
Integrity,Confidentiality,Availability,Access Control
Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism; Modify Memory
Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of a program's implicit security policy. Besides important user data, heap-based overflows can be used to overwrite function pointers that may be living in memory, pointing it to the attacker's code. Even in applications that do not explicitly use function pointers, the run-time will usually leave many in memory. For example, object methods in C++ are generally implemented using function pointers. Even in C programs, there is often a global offset table used by the underlying runtime.
Integrity,Confidentiality,Availability,Access Control,Other
Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism; Other
When the consequence is arbitrary code execution, this can often be used to subvert any other security service.
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