Vulnerability 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 Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Apache | Spamassassin | < 3.4.2 |
| Canonical | Ubuntu Linux | 12.04 |
| 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 |
Related Weaknesses (CWE)
References
- http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00002.html
- http://www.securityfocus.com/bid/105347Third Party AdvisoryVDB Entry
- https://access.redhat.com/errata/RHSA-2018:2916Third Party Advisory
- https://lists.apache.org/thread.html/7f6a16bc0fd0fd5e67c7fd95bd655069a2ac7d1f88e
- https://lists.debian.org/debian-lts-announce/2018/11/msg00016.htmlThird Party Advisory
- https://security.gentoo.org/glsa/201812-07
- https://usn.ubuntu.com/3811-1/Third Party Advisory
- https://usn.ubuntu.com/3811-2/Third Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00002.html
- http://www.securityfocus.com/bid/105347Third Party AdvisoryVDB Entry
- https://access.redhat.com/errata/RHSA-2018:2916Third Party Advisory
- https://lists.apache.org/thread.html/7f6a16bc0fd0fd5e67c7fd95bd655069a2ac7d1f88e
- https://lists.debian.org/debian-lts-announce/2018/11/msg00016.htmlThird Party Advisory
- https://security.gentoo.org/glsa/201812-07
- https://usn.ubuntu.com/3811-1/Third Party Advisory
FAQ
What is CVE-2017-15705?
CVE-2017-15705 is a vulnerability with a CVSS score of 5.3 (MEDIUM). 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 incorrec...
How severe is CVE-2017-15705?
CVE-2017-15705 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2017-15705?
Check the references section above for vendor advisories and patch information. Affected products include: Apache Spamassassin, Canonical Ubuntu Linux, Debian Debian Linux, Redhat Enterprise Linux Desktop, Redhat Enterprise Linux Eus.