CyberSecBulletin
CVE-2022-23408NVD status: Modified

Wolfssl: Use of Insufficiently Random Values

CVE-2022-23408 is a critical-severity use of insufficiently random values vulnerability in Wolfssl, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 5.1.1 as the first without the flaw, so updating Wolfssl to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.48% chance of exploitation within 30 days, higher than 74% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Wolfssl to 5.1.1 or a later version.
  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
WolfsslWolfssl5.0.0 up to, but not including, 5.1.15.1.1

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
NoneAvailability is not affected.

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

Scoring systemScoreSeverityScored by
CVSS 3.19.1CriticalNVD
CVSS 2.06.4MediumNVD

Official description

wolfSSL 5.x before 5.1.1 uses non-random IV values in certain situations. This affects connections (without AEAD) using AES-CBC or DES3 with TLS 1.1 or 1.2 or DTLS 1.1 or 1.2. This occurs because of misplaced memory initialization in BuildMessage in internal.c.

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. Record last changed materially (score, affected products, status or references).

References

Patches and release notes

Other vulnerabilities in Wolfssl

All Wolfssl vulnerabilities

Spotted an error? Tell us.