CyberSecBulletin
CVE-2023-43650NVD status: Analyzed

jumpserver: Weak Password Recovery Mechanism for Forgotten Password

CVE-2023-43650 is a high-severity weak password recovery mechanism for forgotten password vulnerability in jumpserver, with a CVSS 3.1 base score of 7.4 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 2.28.20, 3.7.1 as the first without the flaw, so updating jumpserver to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.6% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update jumpserver to 2.28.20 or 3.7.1, whichever matches your release line, or a later version.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Jumpserverjumpserver>= 2.0.0, < 2.28.20; >= 3.0.0, < 3.7.1; 2.0.0 up to, but not including, 2.28.20; 3.0.0 up to, but not including, 3.7.12.28.20, 3.7.1

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.2HighCNA (github.com)
CVSS 3.17.4HighNVD

Official description

JumpServer is an open source bastion host. The verification code for resetting user's password is vulnerable to brute-force attacks due to the absence of rate limiting. JumpServer provides a feature allowing users to reset forgotten passwords. Affected users are sent a 6-digit verification code, ranging from 000000 to 999999, to facilitate the password reset. Although the code is only available in 1 minute, this window potentially allows for up to 1,000,000 validation attempts. This issue has been addressed in versions 2.28.20 and 3.7.1. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Weak Password Recovery Mechanism for Forgotten Password

The product contains a mechanism for users to recover or change their passwords without knowing the original password, but the mechanism is weak.

How developers prevent this class of flaw

  • Make sure that all input supplied by the user to the password recovery mechanism is thoroughly filtered and validated.
  • Do not use standard weak security questions and use several security questions.
  • Make sure that there is throttling on the number of incorrect answers to a security question. Disable the password recovery functionality after a certain (small) number of incorrect guesses.

More Weak Password Recovery Mechanism for Forgotten Password vulnerabilities (CWE-640)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Technical write-ups (may include proof of concept)

Other vulnerabilities in jumpserver

All jumpserver vulnerabilities

Recent Weak Password Recovery Mechanism for Forgotten Password vulnerabilities

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