CyberSecBulletin
CVE-2019-10068Exploited in the wildNVD status: Analyzed

Kentico Xperience Deserialization of Untrusted Data

CVE-2019-10068 is a critical-severity deserialization of untrusted data vulnerability in Xperience from Kentico, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 10.0.52, 11.0.48, 12.0.15 as the first without the flaw, so updating Xperience to one of those releases or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on March 25, 2022, which means attacks have been observed in the wild.

Patch now

Attackers are already exploiting this vulnerability, according to CISA.

What to do

  1. Update Xperience to 10.0.52 or 11.0.48 or 12.0.15, whichever matches your release line, or a later version.
  2. CISA's required action: Apply updates per vendor instructions.
  3. Read the advisory on devnet.kentico.com for workarounds and exact fixed builds.
  4. 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
KenticoXperience9.0.0 through 9.0.51; 10.0.0 up to, but not including, 10.0.52; 11.0.0 up to, but not including, 11.0.48; 12.0.0 up to, but not including, 12.0.1510.0.52, 11.0.48, 12.0.15

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
HighThe component can be taken down completely.

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

Scoring systemScoreSeverityScored by
CVSS 3.19.8CriticalNVD
CVSS 3.19.8CriticalCISA (ADP)
CVSS 2.07.5HighNVD

Official description

An issue was discovered in Kentico 12.0.x before 12.0.15, 11.0.x before 11.0.48, 10.0.x before 10.0.52, and 9.x versions. Due to a failure to validate security headers, it was possible for a specially crafted request to the staging service to bypass the initial authentication and proceed to deserialize user-controlled .NET object input. This deserialization then led to unauthenticated remote code execution on the server where the Kentico instance was hosted.

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. Added to CISA's Known Exploited Vulnerabilities catalogue.
  3. Deadline for US federal agencies to remediate, set by CISA.
  4. CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: total).
  5. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Technical write-ups (may include proof of concept)

Other vulnerabilities in Xperience

All Xperience vulnerabilities

Recent Deserialization of Untrusted Data vulnerabilities

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