CVE-2021-3712
Description
It was found that openssl assumed ASN.1 strings to be NUL terminated. A malicious actor may be able to force an application into calling openssl function with a specially crafted, non-NUL terminated string to deliberately hit this bug, which may result in a crash of the application, causing a Denial of Service attack, or possibly, memory disclosure. The highest threat from this vulnerability is to data confidentiality and system availability.
Statement
The following Red Hat products do not ship the affected OpenSSL component but rely on the Red Hat Enterprise Linux to consume them:
- Red Hat Satellite
- Red Hat Update Infrastructure
- Red Hat CloudForms
The Red Hat Advanced Cluster Management for Kubernetes is using the vulnerable version of the library, however the vulnerable code path is not reachable.
compat-openssl10 is deprecated and has been removed from RHEL 9 and later. No further patches would be available for this component except on a case by case basis.
Mitigation
Customers should make an attempt to run current binaries/architectures and not rely on compatibility layers to run older binaries/architectures. In case older binaries/architectures are needed, sandboxing should be used to address such problems and guard the bug.
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 | 7.4 | 7.4 | 7.4 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | High | High | High |
| Privileges Required | None | None | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | High | High | High |
| Integrity Impact | None | None | None |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
NVD: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
Acknowledgements
Upstream acknowledges the OpenSSL project (Ingo Schwarze) as the original reporter.
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