CyberSecBulletin
CVE-2024-0263NVD status: Modified

Ultra Mini HTTPd: Improper Resource Shutdown or Release

Published Updated By the CyberSecBulletin desk

CVE-2024-0263 is a high-severity improper resource shutdown or release vulnerability in Ultra Mini HTTPd from ACME, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Ultra Mini HTTPd versions: 1.21. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.4% chance of exploitation within 30 days, higher than 73% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Ultra Mini HTTPd 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
ACMEUltra Mini HTTPd1.21Not 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
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

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

Scoring systemScoreSeverityScored by
CVSS 3.15.3MediumCNA (vuldb.com)
CVSS 3.17.5HighNVD
CVSS 2.05.0MediumCNA (vuldb.com)

Official description

A vulnerability was found in ACME Ultra Mini HTTPd 1.21. It has been classified as problematic. This affects an unknown part of the component HTTP GET Request Handler. The manipulation leads to denial of service. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used. It is recommended to apply a patch to fix this issue. The associated identifier of this vulnerability is VDB-249819.

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

The underlying weakness: Improper Resource Shutdown or Release

The product does not release or incorrectly releases a resource before it is made available for re-use.

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, languages such as Java, Ruby, and Lisp perform automatic garbage collection that releases memory for objects that have been deallocated.
  • It is good practice to be responsible for freeing all resources you allocate and to be consistent with how and where you free memory in a function. If you allocate memory that you intend to free upon completion of the function, you must be sure to free the memory at all exit points for that function including error conditions.
  • Memory should be allocated/freed using matching functions such as malloc/free, new/delete, and new[]/delete[].

More Improper Resource Shutdown or Release vulnerabilities (CWE-404)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Technical write-ups (may include proof of concept)

Recent Improper Resource Shutdown or Release vulnerabilities

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