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CVE-2013-4434· NVD / CVE Program· CNA redhat

Dropbear SSH Server before 2013.59 generates error messages for a failed logon attempt with different time delays depending on whether the u

Noroxi assessment

Priority: Monitor (action score 22/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 5.7% (FIRST EPSS); higher than 92.9% of all records.
  • No special conditions are required; it is repeatable.
  • Fixed version: dropbear (Debian:12) 2012.55-1.4.

Low priority for now. Upgrade to dropbear (Debian:12) 2012.55-1.4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 5.0 · v2.0—Proof of concept Fix available
Published
Oct 25, 2013
Updated
Jun 16, 2026
EPSS
5.7% · 92th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
20 / 40 · 5.0 / 10
CISA KEV
0 / 30 · Not listed
EPSS
2 / 30 · 5.7%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
dropbear ssh projectdropbear ssh

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • dropbear ssh project dropbear sshbefore 2013.59

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12dropbearbefore 2012.55-1.42012.55-1.4

Same product

dropbear ssh project: all records

Other highest-scoring records for the same primary product.

  • CVE-2016-7406Format string vulnerability in Dropbear SSH before 2016.74 allows remote attackers to execute arbitrary code via format string specifiers in
    42Plan
  • CVE-2016-7407The dropbearconvert command in Dropbear SSH before 2016.74 allows attackers to execute arbitrary code via a crafted OpenSSH key file.
    41Plan
  • CVE-2017-9078The server in Dropbear before 2017.75 might allow post-authentication root remote code execution because of a double free in cleanup of TCP
    37Monitor
  • CVE-2016-7408The dbclient in Dropbear SSH before 2016.74 allows remote attackers to execute arbitrary code via a crafted (1) -m or (2) -c argument.
    36Monitor
  • CVE-2020-36254scp.c in Dropbear before 2020.79 mishandles the filename of .
    33Monitor
  • CVE-2021-36369An issue was discovered in Dropbear through 2020.81.
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:dropbear2012.55-1.4 · Debian:12Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:32016-03-20

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. First PoC+876 d
  3. TodayOct 18, 2026+4741 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • No special conditions are required; it is repeatable.

If successful

Confidentiality
P · data can be read
Integrity
none
Availability
none
Attack complexity
Low
Confidentiality impact
P
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-189 · Numeric Errors

CVSS vector

AV:N/AC:L/Au:N/C:P/I:N/A:N

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records