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Default branch: MAIN
Revision 1.2 / (download) - annotate - [select for diffs], Thu Jun 6 17:15:25 2024 UTC (4 hours, 34 minutes ago) by djm
Branch: MAIN
CVS Tags: HEAD
Changes since 1.1: +21 -1 lines
Diff to previous 1.1 (colored)
Add a facility to sshd(8) to penalise particular problematic client behaviours, controlled by two new sshd_config(5) options: PerSourcePenalties and PerSourcePenaltyExemptList. When PerSourcePenalties are enabled, sshd(8) will monitor the exit status of its child pre-auth session processes. Through the exit status, it can observe situations where the session did not authenticate as expected. These conditions include when the client repeatedly attempted authentication unsucessfully (possibly indicating an attack against one or more accounts, e.g. password guessing), or when client behaviour caused sshd to crash (possibly indicating attempts to exploit sshd). When such a condition is observed, sshd will record a penalty of some duration (e.g. 30 seconds) against the client's address. If this time is above a minimum threshold specified by the PerSourcePenalties, then connections from the client address will be refused (along with any others in the same PerSourceNetBlockSize CIDR range). Repeated offenses by the same client address will accrue greater penalties, up to a configurable maximum. A PerSourcePenaltyExemptList option allows certain address ranges to be exempt from all penalties. We hope these options will make it significantly more difficult for attackers to find accounts with weak/guessable passwords or exploit bugs in sshd(8) itself. PerSourcePenalties is off by default, but we expect to enable it automatically in the near future. much feedback markus@ and others, ok markus@
Revision 1.1 / (download) - annotate - [select for diffs], Sat Jan 9 12:10:02 2021 UTC (3 years, 4 months ago) by dtucker
Branch: MAIN
CVS Tags: OPENBSD_7_5_BASE,
OPENBSD_7_5,
OPENBSD_7_4_BASE,
OPENBSD_7_4,
OPENBSD_7_3_BASE,
OPENBSD_7_3,
OPENBSD_7_2_BASE,
OPENBSD_7_2,
OPENBSD_7_1_BASE,
OPENBSD_7_1,
OPENBSD_7_0_BASE,
OPENBSD_7_0,
OPENBSD_6_9_BASE,
OPENBSD_6_9
Add PerSourceMaxStartups and PerSourceNetBlockSize options which provide more fine grained MaxStartups limits. Man page help jmc@, feedback & ok djm@