Security Resilience

CVE-2023-38522

Apache Traffic Server 8.0.0 – 8.1.11

Published
26 July 2024
Modified
03 November 2025
Patch / advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS Score 0.0099 62th percentile
Risk Priority 59 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-38522 is a high-severity HTTP Request/Response Smuggling (CWE-444) vulnerability in Apache Traffic Server. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique LSASS Memory (T1003.001); ranked in the top 38% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SC-7 (Boundary Protection) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Apache Traffic Server accepts characters that are not allowed for HTTP field names and forwards malformed requests to origin servers. This can be utilized for request smuggling and may also lead cache poisoning if the origin servers are vulnerable. This…

more

issue affects Apache Traffic Server: from 8.0.0 through 8.1.10, from 9.0.0 through 9.2.4. Users are recommended to upgrade to version 8.1.11 or 9.2.5, which fixes the issue.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003.001 LSASS Memory Credential Access
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
T1007 System Service Discovery Discovery
Adversaries may try to gather information about registered local system services.
T1010 Application Window Discovery Discovery
Adversaries may attempt to get a listing of open application windows.
T1011 Exfiltration Over Other Network Medium Exfiltration
Adversaries may attempt to exfiltrate data over a different network medium than the command and control channel.
T1016.002 Wi-Fi Discovery Discovery
Adversaries may search for information about Wi-Fi networks, such as network names and passwords, on compromised systems.
T1021.002 SMB/Windows Admin Shares Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-33934Same product: Apache Traffic Server
CVE-2026-58153Same product: Apache Traffic Server
CVE-2024-53868Same product: Apache Traffic Server
CVE-2026-24033Same product: Apache Traffic Server
CVE-2025-65114Same product: Apache Traffic Server
CVE-2026-57834Same product: Apache Traffic Server
CVE-2026-58150Same product: Apache Traffic Server
CVE-2026-58155Same product: Apache Traffic Server
CVE-2024-35161Same product: Apache Traffic Server
CVE-2026-22068Same product: Apache Traffic Server

Affected Assets

apache
traffic server
8.0.0 — 8.1.11 · 9.0.0 — 9.2.5

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V4.1.3
  • V4.2.4
  • V1.5.3
  • V4.1.1

Mitigating Controls (NIST 800-53 r5) AI

Boundary protection at external interfaces can enforce consistent HTTP request/response parsing rules between intermediaries and endpoints.

Validating HTTP inputs at the intermediary prevents malformed messages from being interpreted inconsistently downstream.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

DE.CM-01 partial match
blocks

Network monitoring can detect smuggling attempts via anomalous HTTP traffic or logs, while eliminating the inconsistency directly aids detection of such events.

PR.IR-01 partial match
blocks

Network protections can enforce consistent HTTP proxy/firewall behavior to block smuggling, and removing the weakness helps prevent unauthorized access via request smuggling.

PR.PS-01 partial match
blocks

Configuration management can enforce uniform HTTP parsing rules across intermediaries, directly mitigating inconsistent interpretation.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

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References