CVE-2023-49083
Description
A null-pointer dereference vulnerability was found in python-cryptography during the loading of PKCS7 certificates. Invoking "load_pem_pkcs7_certificates" or "load_der_pkcs7_certificates" can trigger this issue and lead to subsequent segmentation fault and result in a Denial of Service (DoS) for any application aiming to deserialize a PKCS7 blob or certificate. The potential impact includes disruptions in system availability and stability.
Statement
This vulnerability arises when functions like "load_pem_pkcs7_certificates" or "load_der_pkcs7_certificates" are invoked, triggering the issue during the deserialization of PKCS7 blobs or certificates. The moderate rating is based on the fact that the vulnerability can lead to a segmentation fault, posing a risk of disrupting the normal functioning of any application attempting to deserialize the mentioned certificates. While the impact is significant in terms of service denial and potential system instability, the severity is deemed moderate as it does not directly expose sensitive data or allow for remote code execution, focusing primarily on the localized consequences of a DoS scenario.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | 7.5 | 5.9 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | Low | Low | High |
| Privileges Required | None | None | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | None |
| Integrity Impact | None | None | None |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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