CVE-2023-3173Public exploitNetwork attack vector

Account access via unrestricted 2FA guessing

Published Jun 9, 2023 · Updated Jan 6, 2025

Improper 2FA attempt limiting in Froxlor before 2.0.20 allows remote attackers to brute-force a user's second factor. The 2fa_verify path checked each submitted code without incrementing loginfail_count or applying the existing login lockout threshold after failures. A correct primary credential and an account with 2FA enabled are required; guessing the second-factor code grants access as that account.

CVSS severity9.8
Critical
EPSS probability1.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper 2FA attempt limiting in Froxlor before 2.0.20 allows remote attackers to brute-force a user's second factor. The 2fa_verify path checked each submitted code without incrementing loginfail_count or applying the existing login lockout threshold after failures. A correct primary credential and an account with 2FA enabled are required; guessing the second-factor code grants access as that account.

The record

CVE
CVE-2023-3173
Published
Jun 9, 2023
Updated
Jan 6, 2025
Vendor
Froxlor
Product
Froxlor
Classifications
CWE-307, T1110
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 9, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 6, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <2.0.20

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Froxlor · Froxlorversion=unspecified <2.0.20

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8huntr.devCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-307Improper Restriction of Excessive Authentication Attempts
T1110Brute Force

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo