Bug 1693612 (CVE-2019-3883) - CVE-2019-3883 389-ds-base: DoS via hanging secured connections
Summary: CVE-2019-3883 389-ds-base: DoS via hanging secured connections
Status: NEW
Alias: CVE-2019-3883
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Whiteboard: impact=moderate,public=20190412,repor...
Keywords: Security
Depends On: 1668457 1699043 1719720
Blocks: 1690835
TreeView+ depends on / blocked
Reported: 2019-03-28 10:06 UTC by Cedric Buissart 🐶
Modified: 2019-06-28 13:32 UTC (History)
12 users (show)

It was found that encrypted connections did not honor the 'ioblocktimeout' parameter to end blocking requests. As a result, an unauthenticated attacker could repeatedly start a sufficient number of encrypted connections to block all workers, resulting in a denial of service.
Clone Of:
Last Closed:

Attachments (Terms of Use)

Description Cedric Buissart 🐶 2019-03-28 10:06:27 UTC
In 389-ds-base, requests are handled by workers threads. Each sockets will be waited by the worker for at most 'ioblocktimeout' seconds.
However this timeout applies only for un-encrypted requests. Connections using SSL/TLS are not taking this timeout into account during reads, and may hang longer.

An unauthenticated attacker could repeatedly create hanging LDAP requests to hang all the workers, resulting in a Denial of Service.

Comment 5 Salvatore Bonaccorso 2019-04-13 07:43:33 UTC

Is there any further references for this issue? Upstream issue or fixing commits? Thanks already for any hints!


Comment 6 William Brown 2019-04-15 00:49:44 UTC
Upstream does not appear to have been contacted about this issue. Perhaps the developers of 389 at redhat have? We have had some issues in the past with communication of security issues though.


I will be investigating this soon.

Comment 7 thierry bordaz 2019-04-15 08:16 UTC
Created attachment 1555159 [details]
Make sure secure connection enforce the ioblocktimeout

Comment 8 Cedric Buissart 🐶 2019-04-16 08:21:34 UTC

There is a proposed patch uploaded via comment 7.

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