CyberSecBulletin
CVE-2023-4971NVD status: Modified

Weaver Xtreme Theme Support: Deserialization of Untrusted Data

CVE-2023-4971 is a high-severity deserialization of untrusted data vulnerability in Weaver Xtreme Theme Support, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. The record lists version 6.3.1 as the first without the flaw, so updating Weaver Xtreme Theme Support to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.19% chance of exploitation within 30 days, higher than 68% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Weaver Xtreme Theme Support to 6.3.1 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
Weaver Xtreme Theme SupportWeaver Xtreme Theme Supportbefore 6.3.16.3.1

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
HighAdministrator-level access is required first.
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:H/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.2HighNVD
CVSS 3.17.2HighCISA (ADP)

Official description

The Weaver Xtreme Theme Support WordPress plugin before 6.3.1 unserialises the content of an imported file, which could lead to PHP object injections issues when a high privilege user import a malicious file and a suitable gadget chain is present on the blog.

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

The underlying weakness: Deserialization of Untrusted Data

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

How developers prevent this class of flaw

  • If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
  • When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
  • Explicitly define a final object() to prevent deserialization.

More Deserialization of Untrusted Data vulnerabilities (CWE-502)

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)

Recent Deserialization of Untrusted Data vulnerabilities

Spotted an error? Tell us.