CVE-2024-6874

macidn punycode buffer overread

MEDIUM
4.3
CVSS Score
Published: July 24, 2024 at 07:36 AM UTC
Updated: June 17, 2026 at 08:18 AM UTC
2 products affected across 1 vendorLibcurlCurl

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Severity
MEDIUM4.3
Exploit prediction
EPSS 0.8%
SSVC
PoC

Description

libcurl's URL API function [curl_url_get()](https://curl.se/libcurl/c/curl_url_get.html) offers punycode conversions, to and from IDN. Asking to convert a name that is exactly 256 bytes, libcurl ends up reading outside of a stack based buffer when built to use the *macidn* IDN backend. The conversion function then fills up the provided buffer exactly - but does not null terminate the string. This flaw can lead to stack contents accidently getting returned as part of the converted string.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (5)

Mailing ListThird Party Advisory
Source: 2499f714-1537-4658-8207-48ae4bb9eae9
http://www.openwall.com/lists/oss-security/2024/07/24/2
Vendor Advisory
Source: 2499f714-1537-4658-8207-48ae4bb9eae9
https://curl.se/docs/CVE-2024-6874.html
Vendor Advisory
Source: 2499f714-1537-4658-8207-48ae4bb9eae9
https://curl.se/docs/CVE-2024-6874.json
ExploitIssue TrackingTechnical Description
Source: 2499f714-1537-4658-8207-48ae4bb9eae9
https://hackerone.com/reports/2604391
Source: af854a3a-2127-422b-91ae-364da2661108
https://security.netapp.com/advisory/ntap-20240822-0004/

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-125

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