CVE-2024-23185

Public on

Last Modified: UTC

ModerateModerate ImpactWhat does this mean?

Insights vulnerability analysis

View exposed systems

Description

A security issue was found in Dovecot. Very large headers can lead to resource exhaustion when parsing messages. The message-parser normally reads reasonably sized chunks of the message. However, when it feeds them to the message-header-parser, it starts building up a "full_value" buffer out of the smaller chunks. The full_value buffer has no size limit so large headers can cause large memory usage. This issue occurs whether it is a single long header line or a single header split into multiple lines.

A security issue was found in Dovecot. Very large headers can lead to resource exhaustion when parsing messages. The message-parser normally reads reasonably sized chunks of the message. However, when it feeds them to the message-header-parser, it starts building up a "full_value" buffer out of the smaller chunks. The full_value buffer has no size limit so large headers can cause large memory usage. This issue occurs whether it is a single long header line or a single header split into multiple lines.

Statement

This vulnerability is considered moderate rather than important because, while it can lead to resource exhaustion through unbounded memory allocation, its exploitability is limited by several factors. Incoming mail typically passes through an MTA that enforces size limits, significantly reducing the likelihood of an external attacker successfully exploiting the issue. Additionally, the potential for a user to cause a denial-of-service (DoS) attack on themselves by appending large emails is largely self-contained, affecting only the user's session and not posing a broader systemic risk. As a result, the overall impact is mitigated, making it a moderate severity issue.

This vulnerability is considered moderate rather than important because, while it can lead to resource exhaustion through unbounded memory allocation, its exploitability is limited by several factors. Incoming mail typically passes through an MTA that enforces size limits, significantly reducing the likelihood of an external attacker successfully exploiting the issue. Additionally, the potential for a user to cause a denial-of-service (DoS) attack on themselves by appending large emails is largely self-contained, affecting only the user's session and not posing a broader systemic risk. As a result, the overall impact is mitigated, making it a moderate severity issue.

Mitigation

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Additional information

  • Bugzilla 2305910: dovecot: very large headers can cause resource exhaustion when parsing message
  • CWE-770: Allocation of Resources Without Limits or Throttling
  • FAQ: Frequently asked questions about CVE-2024-23185

Common Vulnerability Scoring System (CVSS) Score Details

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 HatNVD

CVSS v3 Base Score

6.8

N/A

Attack Vector

Network

N/A

Attack Complexity

High

N/A

Privileges Required

None

N/A

User Interaction

None

N/A

Scope

Changed

N/A

Confidentiality Impact

None

N/A

Integrity Impact

None

N/A

Availability Impact

High

N/A

CVSS v3 Vector

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

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?

What can I do if my product is listed as "Will not fix"?

What can I do if my product is listed as "Fix deferred"?

What is a mitigation?

I have a Red Hat product but it is not in the above list, is it affected?

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

My product is listed as "Out of Support Scope". What does this mean?

Want to get errata notifications? Sign up here.