CVE-2024-38535Network attack vector

Service interruption via quadratic duplicate-header expansion

Published Jul 11, 2024 · Updated Aug 2, 2024

Resource exhaustion in Suricata before 6.0.20 and 7.0.0 through 7.0.5 allows remote attackers to exhaust memory with crafted HTTP/2 traffic. The HTTP/2 header lookup routines in rust/src/http2/detect.rs concatenate repeated header values into expanding vectors despite HPACK header-name reuse, producing quadratic allocation. No authentication or user interaction is required; traffic must reach a monitored interface with the HTTP/2 parser enabled, and exhaustion interrupts the engine.

CVSS severity7.5
High
EPSS probability1.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Suricata before 6.0.20 and 7.0.0 through 7.0.5 allows remote attackers to exhaust memory with crafted HTTP/2 traffic. The HTTP/2 header lookup routines in rust/src/http2/detect.rs concatenate repeated header values into expanding vectors despite HPACK header-name reuse, producing quadratic allocation. No authentication or user interaction is required; traffic must reach a monitored interface with the HTTP/2 parser enabled, and exhaustion interrupts the engine.

The record

CVE
CVE-2024-38535
Published
Jul 11, 2024
Updated
Aug 2, 2024
Vendor
Open Information Security Foundation
Product
Suricata
Classifications
CWE-770, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 11, 2024CVE 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

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Is a vulnerable build present?

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

  1. Affected versionversion=0 <6.0.20
  2. Affected versionversion=< 6.0.20
  3. Affected versionversion=>= 7.0.0, < 7.0.6
  4. Affected versionversion=7.0.0 <7.0.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Open Information Security Foundation · Suricataversion=0 <6.0.20; version=< 6.0.20; version=>= 7.0.0, < 7.0.6; version=7.0.0 <7.0.6

Published CVSS scores

7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499.004Application or System Exploitation

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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