National Vulnerability Database

National Vulnerability Database

National Vulnerability
Database

CVE-2017-15705 Detail

Current Description

A denial of service vulnerability was identified that exists in Apache SpamAssassin before 3.4.2. The vulnerability arises with certain unclosed tags in emails that cause markup to be handled incorrectly leading to scan timeouts. In Apache SpamAssassin, using HTML::Parser, we setup an object and hook into the begin and end tag event handlers In both cases, the "open" event is immediately followed by a "close" event - even if the tag *does not* close in the HTML being parsed. Because of this, we are missing the "text" event to deal with the object normally. This can cause carefully crafted emails that might take more scan time than expected leading to a Denial of Service. The issue is possibly a bug or design decision in HTML::Parser that specifically impacts the way Apache SpamAssassin uses the module with poorly formed html. The exploit has been seen in the wild but not believed to have been purposefully part of a Denial of Service attempt. We are concerned that there may be attempts to abuse the vulnerability in the future.

Source:  MITRE
Description Last Modified:  09/17/2018
View Analysis Description

Impact

CVSS v3.0 Severity and Metrics:

Base Score: 5.3 MEDIUM
Vector: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L (V3 legend)
Impact Score: 1.4
Exploitability Score: 3.9


Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): Low

CVSS v2.0 Severity and Metrics:

Base Score: 5.0 MEDIUM
Vector: (AV:N/AC:L/Au:N/C:N/I:N/A:P) (V2 legend)
Impact Subscore: 2.9
Exploitability Subscore: 10.0


Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (AU): None
Confidentiality (C): None
Integrity (I): None
Availability (A): Partial
Additional Information:
Allows disruption of service

References to Advisories, Solutions, and Tools

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Hyperlink Resource
http://www.securityfocus.com/bid/105347 Third Party Advisory VDB Entry
https://access.redhat.com/errata/RHSA-2018:2916 Third Party Advisory
https://lists.apache.org/thread.html/7f6a16bc0fd0fd5e67c7fd95bd655069a2ac7d1f88e42d3c853e601c@%3Cannounce.apache.org%3E Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2018/11/msg00016.html Third Party Advisory
https://usn.ubuntu.com/3811-1/ Third Party Advisory
https://usn.ubuntu.com/3811-2/ Third Party Advisory

Technical Details

Vulnerability Type (View All)

Change History

5 change records found - show changes

Quick Info

CVE Dictionary Entry:
CVE-2017-15705
NVD Published Date:
09/17/2018
NVD Last Modified:
12/07/2018