CVE-2018-16840

Publication date 31 October 2018

Last updated 25 August 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

9.8 · Critical

Score breakdown

Description

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.

Read the notes from the security team

Status

Package Ubuntu Release Status
curl 18.10 cosmic
Fixed 7.61.0-1ubuntu2.2
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected

Notes

mdeslaur

introduced by https://github.com/curl/curl/commit/b46cfbc068 in curl 7.59

Severity score breakdown

Parameter Value
Base score 9.8 · Critical
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)

Other references