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.
Hi Is there any further references for this issue? Upstream issue or fixing commits? Thanks already for any hints! Regards, Salvatore
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. https://pagure.io/389-ds-base/issue/50329 I will be investigating this soon.
Created attachment 1555159 [details] Make sure secure connection enforce the ioblocktimeout
Hello, There is a proposed patch uploaded via comment 7.
Upstream fixes : 1.3.8 branch : * https://pagure.io/389-ds-base/c/e26704f0079 1.3.9 branch : * https://pagure.io/389-ds-base/c/dd4b69b5 * https://pagure.io/389-ds-base/c/9a89e779 * https://pagure.io/389-ds-base/c/33ac4f5a 1.4.0 branch : * https://pagure.io/389-ds-base/c/fcf2b5d * https://pagure.io/389-ds-base/c/4950a3e * https://pagure.io/389-ds-base/c/7b0e7f6 master branch : * https://pagure.io/389-ds-base/c/4d9cc24da * https://pagure.io/389-ds-base/c/6d080a0a * https://pagure.io/389-ds-base/c/f35ad371 * https://pagure.io/389-ds-base/c/f20e982c
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2019:1896 https://access.redhat.com/errata/RHSA-2019:1896
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s): https://access.redhat.com/security/cve/cve-2019-3883
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2019:3401 https://access.redhat.com/errata/RHSA-2019:3401