CVE-2018-16840

A heap use-after-free flaw was found in curl versions from 7.59.0 through 7.61.1 in the code related to closing an easy handle. When closing and cleaning up an 'easy' handle in the `Curl_close()` function, the library code first frees a struct (without nulling the pointer) and might then subsequently erroneously write to a struct field within that already freed struct.

Score

CVSS 3.1 9.8 Critical

Status

Analyzed - secalert@redhat.com

Published

2018-10-31

Last modified

2026-04-16

Weaknesses

CWE-416

Affected products

• Ubuntu Linux (Canonical)
• Curl (Haxx)
• Curl (The Curl Project)

References

• http://www.securitytracker.com/id/1042013
• https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16840
• https://curl.haxx.se/docs/CVE-2018-16840.html
• https://github.com/curl/curl/commit/81d135d67155c5295b1033679c606165d4e28f3f
• https://security.gentoo.org/glsa/201903-03
• https://usn.ubuntu.com/3805-1/