CyberSecBulletin
CVE-2024-48928NVD status: Analyzed

Piwigo: Use of Insufficiently Random Values

CVE-2024-48928 is a high-severity use of insufficiently random values vulnerability in Piwigo, 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 Piwigo versions: >= 14.0.0, < 15.0.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.3% 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. Check which version of Piwigo you run against the affected versions below, and install the vendor's latest release.
  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
PiwigoPiwigo>= 14.0.0, < 15.0.0Not 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
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
NoneNothing can be modified.
Availability
NoneAvailability is not affected.

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

Scoring systemScoreSeverityScored by
CVSS 4.02.7LowCNA (github.com)
CVSS 3.17.5HighNVD

Official description

Piwigo is an open source photo gallery application for the web. In versions on the 14.x branch, when installing, the secret_key configuration parameter is set to MD5(RAND()) in MySQL. However, RAND() only has 30 bits of randomness, making it feasible to brute-force the secret key. The CSRF token is constructed partially from the secret key, and this can be used to check if the brute force succeeded. Trying all possible values takes approximately one hour. The impact of this is limited. The auto login key uses the user's password on top of the secret key. The pwg token uses the user's session identifier on top of the secret key. It seems that values for get_ephemeral_key can be generated when one knows the secret key. Version 15.0.0 contains a fix for the issue.

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

The underlying weakness: Use of Insufficiently Random Values

The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.

How developers prevent this class of flaw

  • Use a well-vetted algorithm that is currently considered to be strong by experts in the field, and select well-tested implementations with adequate length seeds. In general, if a pseudo-random number generator is not advertised as being cryptographically secure, then it is probably a statistical PRNG and should not be used in security-sensitive contexts. Pseudo-random number generators can produce predictable numbers if the generator is known and the seed can be guessed. A 256-bit seed is a good starting point for producing a random enough number.
  • Consider a PRNG that re-seeds itself as needed from high quality pseudo-random output sources, such as hardware devices.
  • Use products or modules that conform to FIPS 140-2 to avoid obvious entropy problems. Consult FIPS 140-2 Annex C (Approved Random Number Generators).

More Use of Insufficiently Random Values vulnerabilities (CWE-330)

Timeline

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

References

Other vulnerabilities in Piwigo

All Piwigo vulnerabilities

Recent Use of Insufficiently Random Values vulnerabilities

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