CVE-2017-15705

Advisory lineage Upstream: 0 Downstream: 11
Modified
Published: 17 Sept 2018, 14:00
Last modified:16 Sept 2024, 23:15

Vulnerability Summary

Overall Risk (default)
low
22/100
CVSS Score
5.3 MEDIUM
v3.0 (nvd)
EPSS Score
1.77% LOW
2% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

17 Sept 2018, 14:00
Published
Vulnerability first disclosed
16 Sept 2024, 23:15
Last Modified
Vulnerability information updated

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.

CVSS Metrics

  • v3.0•MEDIUM•Score: 5.3CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
  • v2.0•MEDIUM•Score: 5AV:N/AC:L/Au:N/C:N/I:N/A:P

EPSS Trends

Current EPSS score: 1.77%• Percentile: 83%

Techniques & Countermeasures

  • CWE-20•Improper Input Validation

    The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

Affected Systems

  • apache software foundation•apache spamassassin

    all modern versions before 3.4.2

  • apache•spamassassin

    < 3.4.2

  • canonical•ubuntu_linux

    12.04 | 14.04 | 16.04 | 18.04

  • debian•debian_linux

    8.0

  • redhat•enterprise_linux_desktop

    7.0

  • redhat•enterprise_linux_eus

    7.5

  • redhat•enterprise_linux_server

    7.0

  • redhat•enterprise_linux_workstation

    7.0

References (8)