CVE-2018-6872
Description
From CVE.org
The elf_parse_notes function in elf.c in the Binary File Descriptor (BFD) library (aka libbfd), as distributed in GNU Binutils 2.30, allows remote attackers to cause a denial of service (out-of-bounds read and segmentation violation) via a note with a large alignment.
Statement
The prerequisites for successful exploitation of this bug involves both independent filesystem access as well as the victim to interact with the file created.
- An attacker needs to create a file (such as an ELF file) containing a note section with a large alignment value designed to trigger the out-of-bounds read in the elf_parse_notes function.
- The attacker must convince a user to process the malicious file using a tool that utilizes the vulnerable libbfd library, such as objdump or readelf.
Considering the high bar of prerequites for successful exploitation, RH ProdSec has set the Impact of this vulnerability to "Low"
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 | 3.3 | 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 | Low | High | N/A |
Vector
Red Hat: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
NVD: CVSS:3.0/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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