CVE-2020-29362
Description
From CVE.org
An issue was discovered in p11-kit 0.21.1 through 0.23.21. A heap-based buffer over-read has been discovered in the RPC protocol used by thep11-kit server/remote commands and the client library. When the remote entity supplies a byte array through a serialized PKCS#11 function call, the receiving entity may allow the reading of up to 4 bytes of memory past the heap allocation.
Statement
The p11-kit library is primarily intended to be used locally, in which case the attacker needs to have sufficient permission to access the p11-kit communication. Although there may be use cases of p11-kit being used with a remote entity, all parties must be considered trusted. As a result, Red Hat considers this vulnerability with a Medium severity.
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 | 5.3 | 5.3 | 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 | Low | Low | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Red Hat CVSS v3 Score Explanation
Availability : unless the library is protected with a sanitizer, such as libasan, reading up to 4 bytes past an allocation would not result in a segmentation fault, and thus the would be no loss of availability
Confidentiality : this vulnerability may be used by an attacker to obtain up to 4 bytes beyond the allocation. This might result in a minor disclosure.
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.
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