CyberSecBulletin
CVE-2023-43902NVD status: Modified

Emsigner: Weak Password Recovery Mechanism for Forgotten Password

CVE-2023-43902 is a critical-severity weak password recovery mechanism for forgotten password vulnerability in Emsigner from eMudhra, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Emsigner versions: 2.8.7. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.83% chance of exploitation within 30 days, higher than 58% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of Emsigner you run against the affected versions below, and install the vendor's latest release.
  2. 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
EmudhraEmsigner2.8.7Not stated

Version data comes from NVD's product matching. 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
LowNo special conditions are needed; the attack works reliably.
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
HighThe component can be taken down completely.

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

Scoring systemScoreSeverityScored by
CVSS 3.19.8CriticalNVD
CVSS 3.18.8HighCISA (ADP)

Official description

Incorrect access control in the Forgot Your Password function of eMudhra emSigner v2.8.7 allows unauthenticated attackers to access accounts of all registered users, including those with administrator privileges via a crafted password reset token.

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: poc, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Technical write-ups (may include proof of concept)

Other vulnerabilities in Emsigner

All Emsigner vulnerabilities

Recent Weak Password Recovery Mechanism for Forgotten Password vulnerabilities

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