CVE-2023-20247Network attack vector

Authenticated VPN policy bypass via error handling

Published Nov 1, 2023 · Updated Jun 12, 2025

Authentication bypass in Cisco ASA and FTD Software allows remote authenticated users to evade multiple-certificate VPN authentication. During remote access VPN session establishment, improper error handling accepts crafted requests without enforcing every configured certificate check. A valid username and password, enabled SSL VPN, and a profile requiring multiple-certificate authentication are required; access retains that profile's privileges.

CVSS severity5.0
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Cisco ASA and FTD Software allows remote authenticated users to evade multiple-certificate VPN authentication. During remote access VPN session establishment, improper error handling accepts crafted requests without enforcing every configured certificate check. A valid username and password, enabled SSL VPN, and a profile requiring multiple-certificate authentication are required; access retains that profile's privileges.

The record

CVE
CVE-2023-20247
Published
Nov 1, 2023
Updated
Jun 12, 2025
Vendor
ClamAV
Product
Cisco Adaptive Security Appliance (ASA) Software
Classifications
CWE-288, T1556.006
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 1, 2023CVE publishedPublication date reported by the CVE source.
  2. Jun 12, 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=9.12.1
  2. Affected versionversion=9.12.1.2
  3. Affected versionversion=9.12.1.3
  4. Affected versionversion=9.12.2
  5. Affected versionversion=9.12.2.1
  6. Affected versionversion=9.12.2.4
  7. Affected versionversion=9.12.2.5
  8. Affected versionversion=9.12.2.9
  9. Affected versionversion=9.12.3
  10. Affected versionversion=9.12.3.12
  11. Affected versionversion=9.12.3.2
  12. Affected versionversion=9.12.3.7
  13. Affected versionversion=9.12.3.9
  14. Affected versionversion=9.12.4
  15. Affected versionversion=9.12.4.10
  16. Affected versionversion=9.12.4.13
  17. Affected versionversion=9.12.4.18
  18. Affected versionversion=9.12.4.2
  19. Affected versionversion=9.12.4.24
  20. Affected versionversion=9.12.4.26
  21. Affected versionversion=9.12.4.29
  22. Affected versionversion=9.12.4.30
  23. Affected versionversion=9.12.4.35
  24. Affected versionversion=9.12.4.37
  25. Affected versionversion=9.12.4.38
  26. Affected versionversion=9.12.4.39
  27. Affected versionversion=9.12.4.4
  28. Affected versionversion=9.12.4.40
  29. Affected versionversion=9.12.4.41
  30. Affected versionversion=9.12.4.47
  31. Affected versionversion=9.12.4.48
  32. Affected versionversion=9.12.4.50
  33. Affected versionversion=9.12.4.52
  34. Affected versionversion=9.12.4.54
  35. Affected versionversion=9.12.4.55
  36. Affected versionversion=9.12.4.56
  37. Affected versionversion=9.12.4.58
  38. Affected versionversion=9.12.4.7
  39. Affected versionversion=9.12.4.8
  40. Affected versionversion=9.14.1
  41. Affected versionversion=9.14.1.10
  42. Affected versionversion=9.14.1.15
  43. Affected versionversion=9.14.1.19
  44. Affected versionversion=9.14.1.30
  45. Affected versionversion=9.14.1.6
  46. Affected versionversion=9.14.2
  47. Affected versionversion=9.14.2.13
  48. Affected versionversion=9.14.2.15
  49. Affected versionversion=9.14.2.4
  50. Affected versionversion=9.14.2.8
  51. Affected versionversion=9.14.3
  52. Affected versionversion=9.14.3.1
  53. Affected versionversion=9.14.3.11
  54. Affected versionversion=9.14.3.13
  55. Affected versionversion=9.14.3.15
  56. Affected versionversion=9.14.3.18
  57. Affected versionversion=9.14.3.9
  58. Affected versionversion=9.14.4
  59. Affected versionversion=9.14.4.12
  60. Affected versionversion=9.14.4.13
  61. Affected versionversion=9.14.4.14
  62. Affected versionversion=9.14.4.15
  63. Affected versionversion=9.14.4.17
  64. Affected versionversion=9.14.4.22
  65. Affected versionversion=9.14.4.23
  66. Affected versionversion=9.14.4.6
  67. Affected versionversion=9.14.4.7
  68. Affected versionversion=9.15.1
  69. Affected versionversion=9.15.1.1
  70. Affected versionversion=9.15.1.10
  71. Affected versionversion=9.15.1.15
  72. Affected versionversion=9.15.1.16
  73. Affected versionversion=9.15.1.17
  74. Affected versionversion=9.15.1.21
  75. Affected versionversion=9.15.1.7
  76. Affected versionversion=9.16.1
  77. Affected versionversion=9.16.1.28
  78. Affected versionversion=9.16.2
  79. Affected versionversion=9.16.2.11
  80. Affected versionversion=9.16.2.13
  81. Affected versionversion=9.16.2.14
  82. Affected versionversion=9.16.2.3
  83. Affected versionversion=9.16.2.7
  84. Affected versionversion=9.16.3
  85. Affected versionversion=9.16.3.14
  86. Affected versionversion=9.16.3.15
  87. Affected versionversion=9.16.3.19
  88. Affected versionversion=9.16.3.23
  89. Affected versionversion=9.16.3.3
  90. Affected versionversion=9.16.4
  91. Affected versionversion=9.16.4.14
  92. Affected versionversion=9.16.4.18
  93. Affected versionversion=9.16.4.19
  94. Affected versionversion=9.16.4.9
  95. Affected versionversion=9.17.1
  96. Affected versionversion=9.17.1.10
  97. Affected versionversion=9.17.1.11
  98. Affected versionversion=9.17.1.13
  99. Affected versionversion=9.17.1.15
  100. Affected versionversion=9.17.1.20
  101. Affected versionversion=9.17.1.30
  102. Affected versionversion=9.17.1.7
  103. Affected versionversion=9.17.1.9
  104. Affected versionversion=9.18.1
  105. Affected versionversion=9.18.1.3
  106. Affected versionversion=9.18.2
  107. Affected versionversion=9.18.2.5
  108. Affected versionversion=9.18.2.7
  109. Affected versionversion=9.18.2.8
  110. Affected versionversion=9.18.3
  111. Affected versionversion=9.18.3.39
  112. Affected versionversion=9.18.3.46
  113. Affected versionversion=9.19.1
  114. Affected versionversion=9.19.1.12
  115. Affected versionversion=9.19.1.5
  116. Affected versionversion=9.19.1.9
  117. Affected versionversion=9.8.1
  118. Affected versionversion=9.8.1.5
  119. Affected versionversion=9.8.1.7
  120. Affected versionversion=9.8.2
  121. Affected versionversion=9.8.2.14
  122. Affected versionversion=9.8.2.15
  123. Affected versionversion=9.8.2.17
  124. Affected versionversion=9.8.2.20
  125. Affected versionversion=9.8.2.24
  126. Affected versionversion=9.8.2.26
  127. Affected versionversion=9.8.2.28
  128. Affected versionversion=9.8.2.33
  129. Affected versionversion=9.8.2.35
  130. Affected versionversion=9.8.2.38
  131. Affected versionversion=9.8.2.8
  132. Affected versionversion=9.8.3
  133. Affected versionversion=9.8.3.11
  134. Affected versionversion=9.8.3.14
  135. Affected versionversion=9.8.3.16
  136. Affected versionversion=9.8.3.18
  137. Affected versionversion=9.8.3.21
  138. Affected versionversion=9.8.3.26
  139. Affected versionversion=9.8.3.29
  140. Affected versionversion=9.8.3.8
  141. Affected versionversion=9.8.4
  142. Affected versionversion=9.8.4.10
  143. Affected versionversion=9.8.4.12
  144. Affected versionversion=9.8.4.15
  145. Affected versionversion=9.8.4.17
  146. Affected versionversion=9.8.4.20
  147. Affected versionversion=9.8.4.22
  148. Affected versionversion=9.8.4.25
  149. Affected versionversion=9.8.4.26
  150. Affected versionversion=9.8.4.29
  151. Affected versionversion=9.8.4.3
  152. Affected versionversion=9.8.4.32
  153. Affected versionversion=9.8.4.33
  154. Affected versionversion=9.8.4.34
  155. Affected versionversion=9.8.4.35
  156. Affected versionversion=9.8.4.39
  157. Affected versionversion=9.8.4.40
  158. Affected versionversion=9.8.4.41
  159. Affected versionversion=9.8.4.43
  160. Affected versionversion=9.8.4.44
  161. Affected versionversion=9.8.4.45
  162. Affected versionversion=9.8.4.46
  163. Affected versionversion=9.8.4.48
  164. Affected versionversion=9.8.4.7
  165. Affected versionversion=9.8.4.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

ClamAV · Cisco Adaptive Security Appliance (ASA) Softwareversion=9.12.1; version=9.12.1.2; version=9.12.1.3; version=9.12.2; version=9.12.2.1; version=9.12.2.4; version=9.12.2.5; version=9.12.2.9; version=9.12.3; version=9.12.3.12; version=9.12.3.2; version=9.12.3.7; version=9.12.3.9; version=9.12.4; version=9.12.4.10; version=9.12.4.13; version=9.12.4.18; version=9.12.4.2; version=9.12.4.24; version=9.12.4.26; version=9.12.4.29; version=9.12.4.30; version=9.12.4.35; version=9.12.4.37; version=9.12.4.38; version=9.12.4.39; version=9.12.4.4; version=9.12.4.40; version=9.12.4.41; version=9.12.4.47; version=9.12.4.48; version=9.12.4.50; version=9.12.4.52; version=9.12.4.54; version=9.12.4.55; version=9.12.4.56; version=9.12.4.58; version=9.12.4.7; version=9.12.4.8; version=9.14.1; version=9.14.1.10; version=9.14.1.15; version=9.14.1.19; version=9.14.1.30; version=9.14.1.6; version=9.14.2; version=9.14.2.13; version=9.14.2.15; version=9.14.2.4; version=9.14.2.8; version=9.14.3; version=9.14.3.1; version=9.14.3.11; version=9.14.3.13; version=9.14.3.15; version=9.14.3.18; version=9.14.3.9; version=9.14.4; version=9.14.4.12; version=9.14.4.13; version=9.14.4.14; version=9.14.4.15; version=9.14.4.17; version=9.14.4.22; version=9.14.4.23; version=9.14.4.6; version=9.14.4.7; version=9.15.1; version=9.15.1.1; version=9.15.1.10; version=9.15.1.15; version=9.15.1.16; version=9.15.1.17; version=9.15.1.21; version=9.15.1.7; version=9.16.1; version=9.16.1.28; version=9.16.2; version=9.16.2.11; version=9.16.2.13; version=9.16.2.14; version=9.16.2.3; version=9.16.2.7; version=9.16.3; version=9.16.3.14; version=9.16.3.15; version=9.16.3.19; version=9.16.3.23; version=9.16.3.3; version=9.16.4; version=9.16.4.14; version=9.16.4.18; version=9.16.4.19; version=9.16.4.9; version=9.17.1; version=9.17.1.10; version=9.17.1.11; version=9.17.1.13; version=9.17.1.15; version=9.17.1.20; version=9.17.1.30; version=9.17.1.7; version=9.17.1.9; version=9.18.1; version=9.18.1.3; version=9.18.2; version=9.18.2.5; version=9.18.2.7; version=9.18.2.8; version=9.18.3; version=9.18.3.39; version=9.18.3.46; version=9.19.1; version=9.19.1.12; version=9.19.1.5; version=9.19.1.9; version=9.8.1; version=9.8.1.5; version=9.8.1.7; version=9.8.2; version=9.8.2.14; version=9.8.2.15; version=9.8.2.17; version=9.8.2.20; version=9.8.2.24; version=9.8.2.26; version=9.8.2.28; version=9.8.2.33; version=9.8.2.35; version=9.8.2.38; version=9.8.2.8; version=9.8.3; version=9.8.3.11; version=9.8.3.14; version=9.8.3.16; version=9.8.3.18; version=9.8.3.21; version=9.8.3.26; version=9.8.3.29; version=9.8.3.8; version=9.8.4; version=9.8.4.10; version=9.8.4.12; version=9.8.4.15; version=9.8.4.17; version=9.8.4.20; version=9.8.4.22; version=9.8.4.25; version=9.8.4.26; version=9.8.4.29; version=9.8.4.3; version=9.8.4.32; version=9.8.4.33; version=9.8.4.34; version=9.8.4.35; version=9.8.4.39; version=9.8.4.40; version=9.8.4.41; version=9.8.4.43; version=9.8.4.44; version=9.8.4.45; version=9.8.4.46; version=9.8.4.48; version=9.8.4.7; version=9.8.4.8
ClamAV · Cisco Firepower Threat Defenseversion=6.2.3; version=6.2.3.1; version=6.2.3.10; version=6.2.3.11; version=6.2.3.12; version=6.2.3.13; version=6.2.3.14; version=6.2.3.15; version=6.2.3.16; version=6.2.3.17; version=6.2.3.18; version=6.2.3.2; version=6.2.3.3; version=6.2.3.4; version=6.2.3.5; version=6.2.3.6; version=6.2.3.7; version=6.2.3.8; version=6.2.3.9; version=6.4.0; version=6.4.0.1; version=6.4.0.10; version=6.4.0.11; version=6.4.0.12; version=6.4.0.13; version=6.4.0.14; version=6.4.0.15; version=6.4.0.16; version=6.4.0.2; version=6.4.0.3; version=6.4.0.4; version=6.4.0.5; version=6.4.0.6; version=6.4.0.7; version=6.4.0.8; version=6.4.0.9; version=6.6.0; version=6.6.0.1; version=6.6.1; version=6.6.3; version=6.6.4; version=6.6.5; version=6.6.5.1; version=6.6.5.2; version=6.6.7; version=6.6.7.1; version=6.7.0; version=6.7.0.1; version=6.7.0.2; version=6.7.0.3; version=7.0.0; version=7.0.0.1; version=7.0.1; version=7.0.1.1; version=7.0.2; version=7.0.2.1; version=7.0.3; version=7.0.4; version=7.0.5; version=7.1.0; version=7.1.0.1; version=7.1.0.2; version=7.1.0.3; version=7.2.0; version=7.2.0.1; version=7.2.1; version=7.2.2; version=7.2.3; version=7.2.4; version=7.3.0; version=7.3.1; version=7.3.1.1

Published CVSS scores

5.0CiscoCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-288Authentication Bypass Using an Alternate Path or Channel
T1556.006Multi-Factor Authentication

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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