CVE-2024-2004Public exploit

Protocol restriction bypass via retained default set

Published Mar 27, 2024 · Updated Feb 13, 2025

Protocol restriction bypass in curl 7.85.0 through 8.6.0 allows context-dependent attackers to trigger an explicitly disabled transfer protocol. In protocol2num in lib/setopt.c, an all-negative protocol list returns an error before clearing the existing allowed-protocol bitmap, so the default set remains active. Exploitation requires a caller to disable every available protocol without enabling any; the resulting transfer can use plaintext despite the stated restriction.

CVSS severity3.5
Low
EPSS probability1.68%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Protocol restriction bypass in curl 7.85.0 through 8.6.0 allows context-dependent attackers to trigger an explicitly disabled transfer protocol. In protocol2num in lib/setopt.c, an all-negative protocol list returns an error before clearing the existing allowed-protocol bitmap, so the default set remains active. Exploitation requires a caller to disable every available protocol without enabling any; the resulting transfer can use plaintext despite the stated restriction.

The record

CVE
CVE-2024-2004
Published
Mar 27, 2024
Updated
Feb 13, 2025
Vendor
curl
Product
curl
Classifications
CWE-115, CWE-436
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Mar 27, 2024CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2025Record 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=7.85.0 <=7.85.0
  2. Affected versionversion=7.86.0 <=7.86.0
  3. Affected versionversion=7.87.0 <=7.87.0
  4. Affected versionversion=7.88.0 <=7.88.0
  5. Affected versionversion=7.88.1 <=7.88.1
  6. Affected versionversion=8.0.0 <=8.0.0
  7. Affected versionversion=8.0.1 <=8.0.1
  8. Affected versionversion=8.1.0 <=8.1.0
  9. Affected versionversion=8.1.1 <=8.1.1
  10. Affected versionversion=8.1.2 <=8.1.2
  11. Affected versionversion=8.2.0 <=8.2.0
  12. Affected versionversion=8.2.1 <=8.2.1
  13. Affected versionversion=8.3.0 <=8.3.0
  14. Affected versionversion=8.4.0 <=8.4.0
  15. Affected versionversion=8.5.0 <=8.5.0
  16. Affected versionversion=8.6.0 <=8.6.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

curl · curlversion=7.85.0 <=7.85.0; version=7.86.0 <=7.86.0; version=7.87.0 <=7.87.0; version=7.88.0 <=7.88.0; version=7.88.1 <=7.88.1; version=8.0.0 <=8.0.0; version=8.0.1 <=8.0.1; version=8.1.0 <=8.1.0; version=8.1.1 <=8.1.1; version=8.1.2 <=8.1.2; version=8.2.0 <=8.2.0; version=8.2.1 <=8.2.1; version=8.3.0 <=8.3.0; version=8.4.0 <=8.4.0; version=8.5.0 <=8.5.0; version=8.6.0 <=8.6.0

Published CVSS scores

3.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-115Misinterpretation of Input
CWE-436Interpretation Conflict

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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