DescriptionA 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.
Overall state of this security issue: Running
This issue is currently rated as having important severity.
|National Vulnerability Database|
|National Vulnerability Database||SUSE|
Status of this issue by product and package
Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification.
|SUSE Linux Enterprise Desktop 12 SP3||spamassassin||Affected|
|SUSE Linux Enterprise Module for Basesystem 15 GA||spamassassin||In progress|
|SUSE Linux Enterprise Module for Development Tools 15 GA||spamassassin||In progress|
|SUSE Linux Enterprise Server 11 SP3 LTSS||spamassassin||Affected|
|SUSE Linux Enterprise Server 11 SP4||spamassassin||Affected|
|SUSE Linux Enterprise Server 12 GA LTSS||spamassassin||Affected|
|SUSE Linux Enterprise Server 12 SP1 LTSS||spamassassin||Affected|
|SUSE Linux Enterprise Server 12 SP2 LTSS||spamassassin||Affected|
|SUSE Linux Enterprise Server 12 SP3||spamassassin||Affected|