CVE-2020-11098

Description

From CVE.org

In FreeRDP before version 2.1.2, there is an out-of-bound read in glyph_cache_put. This affects all FreeRDP clients with `+glyph-cache` option enabled This is fixed in version 2.1.2.

Mitigation

Do not use the +glyph_cache option in the freerdp client, which is disabled by default in freerdp-2.0.0.rc4 (shipped with Red Hat Enterprise Linux 7 and 8), but required to connect to xrdp.

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 HatNVDcve.org
Base Score6.56.5N/A
Attack VectorNetworkNetworkN/A
Attack ComplexityLowLowN/A
Privileges RequiredNoneNoneN/A
User InteractionNoneNoneN/A
ScopeUnchangedUnchangedN/A
ConfidentialityLowLowN/A
Integrity ImpactNoneNoneN/A
Availability ImpactLowLowN/A

Vector

Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

Red Hat CVSS v3 Score Explanation

C:L as this is just a simple off-by-one out-of-bounds read and not likely to compromise the confidentiality of sensitive data. A:L because if a crash occurred, it would not be a persistent denial of service and would be only on the client, not the server.

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.

Frequently Asked Questions

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