CyberSecBulletin
CVE-2024-20253NVD status: Modified

Cisco Unified Contact Center Enterprise: Deserialization of Untrusted Data

Published Updated By the CyberSecBulletin desk

CVE-2024-20253 is a critical-severity deserialization of untrusted data vulnerability in Cisco Unified Contact Center Enterprise from Cisco, with a CVSS 3.1 base score of 10.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 2.4% chance of exploitation within 30 days, higher than 84% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Unified Communications Manager to 12.5\(1\)su8 or 14su3, whichever matches your release line, or a later version.
  2. Update Unified Communications Manager Im And Presence Service to 12.5\(1\)su8 or 14.0su3, whichever matches your release line, or a later version.
  3. Update Unity Connection to 12.5\(1\)su8 or 14su3, whichever matches your release line, or a later version.
  4. Read the advisory on sec.cloudapps.cisco.com for workarounds and exact fixed builds.
  5. 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
CiscoCisco Unified Contact Center EnterpriseNot specified in the recordNot stated
CiscoCisco Unity Connection12.0(1)SU1; 12.0(1)SU2; 12.0(1)SU3; 12.0(1)SU4; 12.0(1)SU5; 12.5(1); 12.5(1)SU1; 12.5(1)SU2; and 8 more rangesNot stated
CiscoCisco Unified Communications Manager12.0(1)SU1; 12.0(1)SU2; 12.0(1)SU3; 12.0(1)SU4; 12.0(1)SU5; 12.5(1); 12.5(1)SU1; 12.5(1)SU2; and 9 more rangesNot stated
CiscoCisco Unified Contact Center Express8.5(1); 9.0(2)SU3ES04; 10.0(1)SU1; 10.0(1)SU1ES04; 10.5(1); 10.5(1)SU1; 10.5(1)SU1ES10; 10.6(1); and 32 more rangesNot stated
CiscoCisco Unified Communications Manager IM and Presence Service10.5(1); 10.5(2); 10.5(2a); 10.5(2b); 10.5(2)SU3; 10.5(2)SU2a; 10.5(2)SU4a; 10.5(2)SU4; and 32 more rangesNot stated
CiscoCisco Virtualized Voice Browser11.0(1); 11.5(1); 11.5(1)ES29; 11.5(1)ES32; 11.5(1)_ES43; 11.5(1)_ES54; 11.5(1)_ES27; 11.5(1)ES36; and 32 more rangesNot stated
CiscoCisco Packaged Contact Center Enterprise10.5(1); 10.5(2); 10.5(1)_ES7; 10.5(2)_ES8; 11.0(1); 11.0(2); 11.5(1); 11.6(1); and 6 more rangesNot stated
CiscoCisco Unified Communications Manager / Cisco Unity Connection10.5(2)SU10; 10.5(1); 10.5(1)SU1; 10.5(1)SU1a; 10.5(2); 10.5(2)SU1; 10.5(2)SU2; 10.5(2)SU3; and 32 more rangesNot stated
CiscoUnified Communications Managerbefore 12.5\(1\)su8; 14.0 up to, but not including, 14su312.5\(1\)su8, 14su3
CiscoUnified Communications Manager Im And Presence Servicebefore 12.5\(1\)su8; 14.0 up to, but not including, 14.0su312.5\(1\)su8, 14.0su3
CiscoUnity Connectionbefore 12.5\(1\)su8; 14.0 up to, but not including, 14su312.5\(1\)su8, 14su3
CiscoUnified Contact Center Express12.5\(1\)Not stated
CiscoVirtualized Voice Browser12.5\(1\); 12.6\(1\); 12.6\(2\)Not 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
ChangedThe attack can reach beyond the vulnerable component into other systems.
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:C/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.19.9CriticalCNA (cisco.com)
CVSS 3.110.0CriticalNVD

Official description

A vulnerability in multiple Cisco Unified Communications and Contact Center Solutions products could allow an unauthenticated, remote attacker to execute arbitrary code on an affected device. This vulnerability is due to the improper processing of user-provided data that is being read into memory. An attacker could exploit this vulnerability by sending a crafted message to a listening port of an affected device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with the privileges of the web services user. With access to the underlying operating system, the attacker could also establish root access on the affected device.

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: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Cisco Unified Contact Center Enterprise

All Cisco Unified Contact Center Enterprise vulnerabilities

Recent Deserialization of Untrusted Data vulnerabilities

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