CVE-2017-15705
A denial of service vulnerability was identified that exists in Apache SpamAssassin before 3.4.2. The vulnerability arises with certain…
- 5.3MediumCVSS base score
- 7.9%Exploitation in 30 daysEPSS · top 5.3% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By apache
- 11 months later
· 11 months later
Published
- 6 years later
· 6 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.0 | Medium5.3 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
- EPSS (exploitation in 30 days)
- 7.9% · top 5.3% of all CVEs (9 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Affected products
Apache Software Foundation · Apache SpamAssassin
- affected all modern versions before 3.4.2
References
8
- USN-3811-2 (opens in a new tab)vendor-advisoryx_refsource_UBUNTUx_transferred
- USN-3811-1 (opens in a new tab)vendor-advisoryx_refsource_UBUNTUx_transferred
- GLSA-201812-07 (opens in a new tab)vendor-advisoryx_refsource_GENTOOx_transferred
- [announce] 20180916 [SECURITY] Apache SpamAssassin 3.4.2 resolves CVE-2017-15705, CVE-2016-1238, CVE-2018-11780 & CVE-2018-11781 (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- RHSA-2018:2916 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- 105347 (opens in a new tab)vdb-entryx_refsource_BIDx_transferred
- [debian-lts-announce] 20181113 [SECURITY] [DLA 1578-1] spamassassin security update (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- openSUSE-SU-2019:1831 (opens in a new tab)vendor-advisoryx_refsource_SUSEx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2017-7138 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2017-15705)Record last updated .