CVE-2020-35493
Description
A flaw was found in Binutils in bfd/pef.c. This flaw allows an attacker who can submit a crafted PEF file to be parsed by objdump to cause a heap buffer overflow, leading to an out-of-bounds read. The highest threat from this vulnerability is to system availability.
Statement
Binutils as shipped with Red Hat Enterprise Linux 8's GCC Toolset 10 and Red Hat Developer Toolset 10 are not affected by this flaw because the versions shipped have already received the patch.
The issue is classified as low severity primarily because binutils is not typically exposed to untrusted inputs in most environments, limiting its exploitation potential. The memory leak in bfd_pef_parse_function_stubs only triggers during the parsing of malformed files, which would require an attacker to convince a user to process a malicious file. Moreover, binutils does not handle privileged operations, meaning exploitation is unlikely to lead to system compromise or escalation of privileges. Additionally, the impact is localized to the application itself, without affecting the broader system or network security.
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 | 5.5 | 5.5 | 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 | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/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.
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