CVE-2013-4434

Dropbear SSH < 2013.59 - Username Enumeration via Timing Attack

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2013-4434. PoCs published by styx00.

AI-analyzed exploit summary This script checks for CVE-2013-4434 by measuring time delays in Dropbear SSH Server's error messages to determine valid usernames. It uses 'sshpass' to automate login attempts with a provided wordlist.

Description

Dropbear SSH Server before 2013.59 generates error messages for a failed logon attempt with different time delays depending on whether the user account exists, which allows remote attackers to discover valid usernames.

Exploits (1)

nomisec SCANNER 3 stars
by styx00 · poc
https://github.com/styx00/Dropbear_CVE-2013-4434

This script checks for CVE-2013-4434 by measuring time delays in Dropbear SSH Server's error messages to determine valid usernames. It uses 'sshpass' to automate login attempts with a provided wordlist.

Classification
Scanner 100%
Attack Type
Info Leak
Complexity
Trivial
Reliability
Reliable
Target: Dropbear SSH Server before 2013.59
No auth needed
Prerequisites: sshpass installed · wordlist of usernames · network access to target
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (8)

Core 8
Core References
Vendor Advisory third-party-advisory x_refsource_secunia
http://secunia.com/advisories/55173
Vendor Advisory x_refsource_confirm
https://matt.ucc.asn.au/dropbear/CHANGES
Third Party Advisory, VDB Entry vdb-entry x_refsource_bid
http://www.securityfocus.com/bid/62993
Mailing List, Third Party Advisory mailing-list x_refsource_mlist
http://www.openwall.com/lists/oss-security/2013/10/16/11
Third Party Advisory vendor-advisory x_refsource_suse
http://lists.opensuse.org/opensuse-updates/2013-11/msg00046.html
Third Party Advisory x_refsource_confirm
https://support.citrix.com/article/CTX216642
Third Party Advisory vendor-advisory x_refsource_suse
http://lists.opensuse.org/opensuse-updates/2013-10/msg00061.html
Patch, Third Party Advisory x_refsource_confirm
https://secure.ucc.asn.au/hg/dropbear/rev/d7784616409a

Scores

EPSS 0.0575
EPSS Percentile 92.1%

Details

CWE
CWE-189
Status published
Products (1)
dropbear_ssh_project/dropbear_ssh < 2013.59
Published Oct 25, 2013
Tracked Since Feb 18, 2026