CVE-2021-3711
Description
A flaw was found in openssl. A miscalculation of a buffer size was found in openssl's SM2 decryption function, allowing up to 62 arbitrary bytes to be written outside of the buffer. A remote attacker could use this flaw to crash an application supporting SM2 signature or encryption algorithm, or, possibly, execute arbitrary code with the permissions of the user running that application. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Statement
OpenSSL packages shipped with Red Hat Enterprise Linux 8 are not compiled with support for SM2 algorithm and therefore are not affected by this flaw. Packages shipped with Red Hat Enterprise Linux 7 and older do not support the SM2 algorithm.
The Red Hat Advanced Cluster Management for Kubernetes 2.3.1 and the previous versions are using the vulnerable version of the OpenSSL library, however the vulnerable code path is not reachable.
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 | 9.8 | 9.8 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
Acknowledgements
Upstream acknowledges the OpenSSL project (John Ouyang) as the original reporter.
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