CVE-2024-20253Network attack vector

Unauthenticated command execution via unsafe Java deserialization

Published Jan 26, 2024 · Updated May 29, 2025

Unsafe Java deserialization in affected Cisco unified communications products allows remote attackers to execute operating-system commands. A listening service reads crafted user-provided data into memory and deserializes it without restricting the objects that can be created or invoked. The affected services are exposed in default configurations; no authentication is required, and successful code execution can be escalated to root access.

CVSS severity9.9
Critical
EPSS probability2.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unsafe Java deserialization in affected Cisco unified communications products allows remote attackers to execute operating-system commands. A listening service reads crafted user-provided data into memory and deserializes it without restricting the objects that can be created or invoked. The affected services are exposed in default configurations; no authentication is required, and successful code execution can be escalated to root access.

The record

CVE
CVE-2024-20253
Published
Jan 26, 2024
Updated
May 29, 2025
Vendor
ClamAV
Product
Cisco Unified Contact Center Express
Classifications
CWE-502, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 26, 2024CVE publishedPublication date reported by the CVE source.
  2. May 29, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0(1)SU1
  2. Affected versionversion=10.0(1)SU1ES04
  3. Affected versionversion=10.5(1)
  4. Affected versionversion=10.5(1)SU1
  5. Affected versionversion=10.5(1)SU1ES10
  6. Affected versionversion=10.6(1)
  7. Affected versionversion=10.6(1)SU1
  8. Affected versionversion=10.6(1)SU2
  9. Affected versionversion=10.6(1)SU2ES04
  10. Affected versionversion=10.6(1)SU3
  11. Affected versionversion=10.6(1)SU3ES01
  12. Affected versionversion=10.6(1)SU3ES02
  13. Affected versionversion=10.6(1)SU3ES03
  14. Affected versionversion=11.0(1)SU1
  15. Affected versionversion=11.0(1)SU1ES02
  16. Affected versionversion=11.0(1)SU1ES03
  17. Affected versionversion=11.5(1)ES01
  18. Affected versionversion=11.5(1)SU1
  19. Affected versionversion=11.5(1)SU1ES01
  20. Affected versionversion=11.5(1)SU1ES02
  21. Affected versionversion=11.5(1)SU1ES03
  22. Affected versionversion=11.6(1)
  23. Affected versionversion=11.6(1)ES01
  24. Affected versionversion=11.6(1)ES02
  25. Affected versionversion=11.6(2)
  26. Affected versionversion=11.6(2)ES01
  27. Affected versionversion=11.6(2)ES02
  28. Affected versionversion=11.6(2)ES03
  29. Affected versionversion=11.6(2)ES04
  30. Affected versionversion=11.6(2)ES05
  31. Affected versionversion=11.6(2)ES06
  32. Affected versionversion=11.6(2)ES07
  33. Affected versionversion=11.6(2)ES08
  34. Affected versionversion=12.0(1)
  35. Affected versionversion=12.0(1)ES01
  36. Affected versionversion=12.0(1)ES02
  37. Affected versionversion=12.0(1)ES03
  38. Affected versionversion=12.0(1)ES04
  39. Affected versionversion=12.5(1)
  40. Affected versionversion=12.5(1)ES01
  41. Affected versionversion=12.5(1)ES02
  42. Affected versionversion=12.5(1)ES03
  43. Affected versionversion=12.5(1)_SU01_ES01
  44. Affected versionversion=12.5(1)_SU01_ES02
  45. Affected versionversion=12.5(1)_SU01_ES03
  46. Affected versionversion=12.5(1)_SU02_ES01
  47. Affected versionversion=12.5(1)_SU02_ES02
  48. Affected versionversion=12.5(1)_SU02_ES03
  49. Affected versionversion=12.5(1)_SU02_ES04
  50. Affected versionversion=12.5(1)_SU03_ES01
  51. Affected versionversion=12.5(1)_SU03_ES02
  52. Affected versionversion=12.5(1)_SU03_ES03
  53. Affected versionversion=12.5(1)_SU03_ES04
  54. Affected versionversion=12.5(1)SU1
  55. Affected versionversion=12.5(1)SU2
  56. Affected versionversion=12.5(1)SU3
  57. Affected versionversion=8.5(1)
  58. Affected versionversion=9.0(2)SU3ES04

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco Unified Contact Center Expressversion=10.0(1)SU1; version=10.0(1)SU1ES04; version=10.5(1); version=10.5(1)SU1; version=10.5(1)SU1ES10; version=10.6(1); version=10.6(1)SU1; version=10.6(1)SU2; version=10.6(1)SU2ES04; version=10.6(1)SU3; version=10.6(1)SU3ES01; version=10.6(1)SU3ES02; version=10.6(1)SU3ES03; version=11.0(1)SU1; version=11.0(1)SU1ES02; version=11.0(1)SU1ES03; version=11.5(1)ES01; version=11.5(1)SU1; version=11.5(1)SU1ES01; version=11.5(1)SU1ES02; version=11.5(1)SU1ES03; version=11.6(1); version=11.6(1)ES01; version=11.6(1)ES02; version=11.6(2); version=11.6(2)ES01; version=11.6(2)ES02; version=11.6(2)ES03; version=11.6(2)ES04; version=11.6(2)ES05; version=11.6(2)ES06; version=11.6(2)ES07; version=11.6(2)ES08; version=12.0(1); version=12.0(1)ES01; version=12.0(1)ES02; version=12.0(1)ES03; version=12.0(1)ES04; version=12.5(1); version=12.5(1)ES01; version=12.5(1)ES02; version=12.5(1)ES03; version=12.5(1)_SU01_ES01; version=12.5(1)_SU01_ES02; version=12.5(1)_SU01_ES03; version=12.5(1)_SU02_ES01; version=12.5(1)_SU02_ES02; version=12.5(1)_SU02_ES03; version=12.5(1)_SU02_ES04; version=12.5(1)_SU03_ES01; version=12.5(1)_SU03_ES02; version=12.5(1)_SU03_ES03; version=12.5(1)_SU03_ES04; version=12.5(1)SU1; version=12.5(1)SU2; version=12.5(1)SU3; version=8.5(1); version=9.0(2)SU3ES04
ClamAV · Cisco Virtualized Voice Browserversion=11.0(1); version=11.5(1); version=11.5(1)ES27; version=11.5(1)_ES27; version=11.5(1)ES29; version=11.5(1)_ES29; version=11.5(1)ES32; version=11.5(1)_ES32; version=11.5(1)ES36; version=11.5(1)_ES36; version=11.5(1)ES43; version=11.5(1)_ES43; version=11.5(1)_ES53; version=11.5(1)_ES54; version=11.6(1); version=11.6(1)_ES22; version=11.6(1)_ES80; version=11.6(1)_ES81; version=11.6(1)_ES82; version=11.6(1)_ES83; version=11.6(1)_ES84; version=11.6(1)_ES85; version=11.6(1)_ES86; version=11.6(1)_ES87; version=11.6(1)_ES88; version=12.0(1); version=12.0(1)_ES01; version=12.0(1)_ES02; version=12.0(1)_ES03; version=12.0(1)_ES04; version=12.0(1)_ES05; version=12.0(1)_ES06; version=12.0(1)_ES07; version=12.0(1)_ES08; version=12.5(1); version=12.5(1)_ES02; version=12.5(1)_ES03; version=12.5(1)_ES04; version=12.5(1)_ES06; version=12.5(1)_ES07; version=12.5(1)_ES08; version=12.5(1)_ES09; version=12.5(1)_ES10; version=12.5(1)_ES11; version=12.5(1)_ES12; version=12.5(1)_ES14; version=12.5(1)_ES15; version=12.5(1)SU; version=12.5(1)_SU; version=12.5(1)_SU_ES01; version=12.5(1)_SU_ES02; version=12.5(2)_ET; version=12.6(1); version=12.6(1)_ES01; version=12.6(1)_ES02; version=12.6(1)_ES03; version=12.6(1)_ES04; version=12.6(1)_ES05; version=12.6(1)_ES06; version=12.6(1)_ES07; version=12.6(1)_ES08; version=12.6(1)_ES09; version=12.6(2); version=12.6(2)_ES01; version=12.6(2)_ES02; version=12.6(2)_ES03; version=12.6(2)_ET01
ClamAV · Cisco Unified Communications Manager IM and Presence Serviceversion=10.0(1); version=10.0(1)SU1; version=10.0(1)SU2; version=10.5(1); version=10.5(1)SU1; version=10.5(1)SU2; version=10.5(1)SU3; version=10.5(2); version=10.5(2a); version=10.5(2b); version=10.5(2)SU1; version=10.5(2)SU2; version=10.5(2)SU2a; version=10.5(2)SU3; version=10.5(2)SU4; version=10.5(2)SU4a; version=11.0(1); version=11.0(1)SU1; version=11.5(1); version=11.5(1)SU1; version=11.5(1)SU10; version=11.5(1)SU11; version=11.5(1)SU2; version=11.5(1)SU3; version=11.5(1)SU3a; version=11.5(1)SU4; version=11.5(1)SU5; version=11.5(1)SU5a; version=11.5(1)SU6; version=11.5(1)SU7; version=11.5(1)SU8; version=11.5(1)SU9; version=12.5(1); version=12.5(1)SU1; version=12.5(1)SU2; version=12.5(1)SU3; version=12.5(1)SU4; version=12.5(1)SU5; version=12.5(1)SU6; version=12.5(1)SU7; version=14; version=14SU1; version=14SU2; version=14SU2a
ClamAV · Cisco Unified Communications Managerversion=12.0(1)SU1; version=12.0(1)SU2; version=12.0(1)SU3; version=12.0(1)SU4; version=12.0(1)SU5; version=12.5(1); version=12.5(1)SU1; version=12.5(1)SU2; version=12.5(1)SU3; version=12.5(1)SU4; version=12.5(1)SU5; version=12.5(1)SU6; version=12.5(1)SU7; version=12.5(1)SU7a; version=14; version=14SU1; version=14SU2
ClamAV · Cisco Unified Contact Center Enterpriseversion=N/A
ClamAV · Cisco Packaged Contact Center Enterpriseversion=10.5(1); version=10.5(1)_ES7; version=10.5(2); version=10.5(2)_ES8; version=11.0(1); version=11.0(2); version=11.5(1); version=11.6(1); version=11.6(2); version=12.0(1); version=12.5(1); version=12.5(2); version=12.6(1); version=12.6(2)
ClamAV · Cisco Unity Connectionversion=12.0(1)SU1; version=12.0(1)SU2; version=12.0(1)SU3; version=12.0(1)SU4; version=12.0(1)SU5; version=12.5(1); version=12.5(1)SU1; version=12.5(1)SU2; version=12.5(1)SU3; version=12.5(1)SU4; version=12.5(1)SU5; version=12.5(1)SU6; version=12.5(1)SU7; version=14; version=14SU1; version=14SU2

Published CVSS scores

9.9CiscoCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:H/E:X/RL:X/RC:X

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1210Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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