CVE-2024-12085

Description

A flaw was found in rsync which could be triggered when rsync compares file checksums. This flaw allows an attacker to manipulate the checksum length (s2length) to cause a comparison between a checksum and uninitialized memory and leak one byte of uninitialized stack data at a time.

Statement

This vulnerability is rated as having Important impact as it helps bypass Address Space Layout Randomization (ASLR). ASLR is a memory protection system which makes the exploitation of memory corruption vulnerabilities more difficult.

Mitigation

Seeing as this vulnerability relies on information leakage coming from the presence of data in the uninitialized memory of the `sum2` buffer, a potential mitigation involves compiling rsync with the `-ftrivial-auto-var-init=zero` option set. This mitigates the issue because it initializes the `sum2` variable's memory with zeroes to prevent uninitialized memory disclosure.

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 Score7.5N/A7.5
Attack VectorNetworkN/ANetwork
Attack ComplexityLowN/ALow
Privileges RequiredNoneN/ANone
User InteractionNoneN/ANone
ScopeUnchangedN/AUnchanged
ConfidentialityHighN/AHigh
Integrity ImpactNoneN/ANone
Availability ImpactNoneN/ANone

Vector

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

cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Understanding the Weakness (CWE)

Confidentiality

Technical Impact: Read Memory; Read Application Data

When reusing a resource such as memory or a program variable, the original contents of that resource may not be cleared before it is sent to an untrusted party.

Availability

Technical Impact: DoS: Crash, Exit, or Restart

The uninitialized resource may contain values that cause program flow to change in ways that the programmer did not intend.

Acknowledgements

Red Hat would like to thank Jasiel Spelman (Google), Pedro Gallegos (Google), and Simon Scannell (Google) for reporting this issue.

Frequently Asked Questions

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