CVE-2023-5535
Description
A heap-based buffer overflow vulnerability was found in some affected packages of Vim. This flaw allows an attacker to send a specially crafted file that could lead to a complete system compromise when opened by a victim.
Statement
Red Hat Product Security has rated this issue as having a Low security impact, because the "victim" has to run an untrusted file IN SCRIPT MODE. Someone who is running untrusted files in script mode is equivalent to someone just taking a random python script and running it.
Since Red Hat Enterprise Linux 6, 7 are Out-of-Support-Scope for Low/Moderate flaws, the issue is not currently planned to be addressed in future updates for RHEL-6,7. Only Important and Critical severity flaws will be addressed at this time.
For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/ and Red Hat Enterprise Linux Life Cycle & Updates Policy: https://access.redhat.com/support/policy/updates/errata/.
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 | 3.3 | 7.8 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | Required | Required | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | High | N/A |
| Integrity Impact | None | High | N/A |
| Availability Impact | Low | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
NVD: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Red Hat CVSS v3 Score Explanation
C:N, I:N:- because as per attack scenario, the victim user running vim with a malicious file (e.g. coming from an attacker) in -s [Script mode]. As such a crash does not pose any real security risk, unless it can be proven that the triggered issue can be used to send/modify valuable information to/by a remote/local attacker. So, most likely it will cause DoS, and crashing the application would not be a persistent denial of service, as an application should be relaunched and victim needs to reopen the malicious file again to re-crash. Hence, A:L.
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory
The use of previously freed memory may corrupt valid data, if the memory area in question has been allocated and used properly elsewhere.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If chunk consolidation occurs after the use of previously freed data, the process may crash when invalid data is used as chunk information.
Confidentiality
Technical Impact: Read Memory
Read operations on freed memory can sometimes leak sensitive information instead of causing a crash
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If malicious data is entered before chunk consolidation can take place, it may be possible to take advantage of a write-what-where primitive to execute arbitrary code. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.
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