CyberSecBulletin
CVE-2022-31086NVD status: Modified

lam: Unrestricted Upload of File with Dangerous Type

Published Updated By the CyberSecBulletin desk

CVE-2022-31086 is a high-severity unrestricted upload of file with dangerous type vulnerability in lam from LDAPAccountManager, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected lam versions: < 8.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 2.29% chance of exploitation within 30 days, higher than 83% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update LDAP Account Manager to 8.0 or a later version.
  2. Read the advisory on github.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
LDAPAccountManagerlam< 8.0Not stated
Ldap-account-managerLDAP Account Managerbefore 8.08.0
DebianDebian Linux11.0Not stated

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
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
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:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.8HighNVD
CVSS 3.06.6MediumCNA (github.com)
CVSS 2.06.0MediumNVD

Official description

LDAP Account Manager (LAM) is a webfrontend for managing entries (e.g. users, groups, DHCP settings) stored in an LDAP directory. In versions prior to 8.0 incorrect regular expressions allow to upload PHP scripts to config/templates/pdf. This vulnerability could lead to a Remote Code Execution if the /config/templates/pdf/ directory is accessible for remote users. This is not a default configuration of LAM. This issue has been fixed in version 8.0. There are no known workarounds for this issue.

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

The underlying weakness: Unrestricted Upload of File with Dangerous Type

The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.

How developers prevent this class of flaw

  • Generate a new, unique filename for an uploaded file instead of using the user-supplied filename, so that no external input is used at all.
  • When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
  • Consider storing the uploaded files outside of the web document root entirely. Then, use other mechanisms to deliver the files dynamically.

More Unrestricted Upload of File with Dangerous Type vulnerabilities (CWE-434)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in lam

All lam vulnerabilities

Recent Unrestricted Upload of File with Dangerous Type vulnerabilities

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