CVE-2023-20275Public exploitNetwork attack vector

VPN user impersonation via unchecked inner source IP

Published Dec 12, 2023 · Updated Aug 2, 2024

IP address spoofing in Cisco ASA and FTD Software allows remote authenticated users to impersonate another AnyConnect VPN user. After decrypting a tunneled packet, the AnyConnect SSL VPN path fails to verify that its inner source IP belongs to the sending session. Exploitation requires an authenticated VPN tunnel and crafted traffic; it sends one-way packets under another user's address but cannot receive replies.

CVSS severity4.1
Medium
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

IP address spoofing in Cisco ASA and FTD Software allows remote authenticated users to impersonate another AnyConnect VPN user. After decrypting a tunneled packet, the AnyConnect SSL VPN path fails to verify that its inner source IP belongs to the sending session. Exploitation requires an authenticated VPN tunnel and crafted traffic; it sends one-way packets under another user's address but cannot receive replies.

The record

CVE
CVE-2023-20275
Published
Dec 12, 2023
Updated
Aug 2, 2024
Vendor
ClamAV
Product
Cisco Adaptive Security Appliance (ASA) Software
Classifications
CWE-346, T1036
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 12, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record 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=9.16.4.27
  95. Affected versionversion=9.16.4.9
  96. Affected versionversion=9.17.1
  97. Affected versionversion=9.17.1.10
  98. Affected versionversion=9.17.1.11
  99. Affected versionversion=9.17.1.13
  100. Affected versionversion=9.17.1.15
  101. Affected versionversion=9.17.1.20
  102. Affected versionversion=9.17.1.30
  103. Affected versionversion=9.17.1.7
  104. Affected versionversion=9.17.1.9
  105. Affected versionversion=9.18.1
  106. Affected versionversion=9.18.1.3
  107. Affected versionversion=9.18.2
  108. Affected versionversion=9.18.2.5
  109. Affected versionversion=9.18.2.7
  110. Affected versionversion=9.18.2.8
  111. Affected versionversion=9.18.3
  112. Affected versionversion=9.18.3.39
  113. Affected versionversion=9.18.3.46
  114. Affected versionversion=9.19.1
  115. Affected versionversion=9.19.1.12
  116. Affected versionversion=9.19.1.5
  117. Affected versionversion=9.19.1.9
  118. Affected versionversion=9.8.1
  119. Affected versionversion=9.8.1.5
  120. Affected versionversion=9.8.1.7
  121. Affected versionversion=9.8.2
  122. Affected versionversion=9.8.2.14
  123. Affected versionversion=9.8.2.15
  124. Affected versionversion=9.8.2.17
  125. Affected versionversion=9.8.2.20
  126. Affected versionversion=9.8.2.24
  127. Affected versionversion=9.8.2.26
  128. Affected versionversion=9.8.2.28
  129. Affected versionversion=9.8.2.33
  130. Affected versionversion=9.8.2.35
  131. Affected versionversion=9.8.2.38
  132. Affected versionversion=9.8.2.8
  133. Affected versionversion=9.8.3
  134. Affected versionversion=9.8.3.11
  135. Affected versionversion=9.8.3.14
  136. Affected versionversion=9.8.3.16
  137. Affected versionversion=9.8.3.18
  138. Affected versionversion=9.8.3.21
  139. Affected versionversion=9.8.3.26
  140. Affected versionversion=9.8.3.29
  141. Affected versionversion=9.8.3.8
  142. Affected versionversion=9.8.4
  143. Affected versionversion=9.8.4.10
  144. Affected versionversion=9.8.4.12
  145. Affected versionversion=9.8.4.15
  146. Affected versionversion=9.8.4.17
  147. Affected versionversion=9.8.4.20
  148. Affected versionversion=9.8.4.22
  149. Affected versionversion=9.8.4.25
  150. Affected versionversion=9.8.4.26
  151. Affected versionversion=9.8.4.29
  152. Affected versionversion=9.8.4.3
  153. Affected versionversion=9.8.4.32
  154. Affected versionversion=9.8.4.33
  155. Affected versionversion=9.8.4.34
  156. Affected versionversion=9.8.4.35
  157. Affected versionversion=9.8.4.39
  158. Affected versionversion=9.8.4.40
  159. Affected versionversion=9.8.4.41
  160. Affected versionversion=9.8.4.43
  161. Affected versionversion=9.8.4.44
  162. Affected versionversion=9.8.4.45
  163. Affected versionversion=9.8.4.46
  164. Affected versionversion=9.8.4.48
  165. Affected versionversion=9.8.4.7
  166. 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=9.16.4.27; 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=7.0.6; 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

4.1Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:L/A:N/E:X/RL:X/RC:X
4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

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 exploitPublished

Weakness, pattern, technique

CWE-346Origin Validation Error
T1036Masquerading

Public exploit references

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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