Search for vulnerabilities
Vulnerability details: VCID-p1sw-ra86-akau
Vulnerability ID VCID-p1sw-ra86-akau
Aliases CVE-2018-16840
Summary 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.
Status Published
Exploitability 0.5
Weighted Severity 8.8
Risk 4.4
Affected and Fixed Packages Package Details
Weaknesses (1)
CWE-416 Use After Free
System Score Found at
cvssv3 5.0 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2018-16840.json
epss 0.00316 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
epss 0.00322 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
epss 0.00322 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
epss 0.00322 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
epss 0.00322 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
epss 0.00322 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
epss 0.00322 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
epss 0.00322 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
epss 0.00322 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
epss 0.00322 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
epss 0.00322 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
epss 0.00322 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
epss 0.00322 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
epss 0.00322 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
epss 0.00322 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
epss 0.00322 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
epss 0.00322 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
epss 0.00438 https://api.first.org/data/v1/epss?cve=CVE-2018-16840
cvssv3.1 Low https://curl.se/docs/CVE-2018-16840.html
cvssv3 4.3 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
cvssv2 7.5 https://nvd.nist.gov/vuln/detail/CVE-2018-16840
cvssv3.1 9.8 https://nvd.nist.gov/vuln/detail/CVE-2018-16840
archlinux High https://security.archlinux.org/AVG-795
archlinux High https://security.archlinux.org/AVG-796
archlinux High https://security.archlinux.org/AVG-797
archlinux High https://security.archlinux.org/AVG-798
archlinux High https://security.archlinux.org/AVG-799
archlinux High https://security.archlinux.org/AVG-800
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2018-16840.json
https://api.first.org/data/v1/epss?cve=CVE-2018-16840
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16840
https://curl.haxx.se/docs/CVE-2018-16840.html
https://curl.se/docs/CVE-2018-16840.html
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-16840
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
https://github.com/curl/curl/commit/81d135d67155c5295b1033679c606165d4e28f3f
https://security.gentoo.org/glsa/201903-03
http://www.securitytracker.com/id/1042013
1642203 https://bugzilla.redhat.com/show_bug.cgi?id=1642203
ASA-201811-4 https://security.archlinux.org/ASA-201811-4
ASA-201811-5 https://security.archlinux.org/ASA-201811-5
ASA-201811-6 https://security.archlinux.org/ASA-201811-6
ASA-201811-7 https://security.archlinux.org/ASA-201811-7
ASA-201811-8 https://security.archlinux.org/ASA-201811-8
ASA-201811-9 https://security.archlinux.org/ASA-201811-9
AVG-795 https://security.archlinux.org/AVG-795
AVG-796 https://security.archlinux.org/AVG-796
AVG-797 https://security.archlinux.org/AVG-797
AVG-798 https://security.archlinux.org/AVG-798
AVG-799 https://security.archlinux.org/AVG-799
AVG-800 https://security.archlinux.org/AVG-800
cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*
CVE-2018-16840 https://nvd.nist.gov/vuln/detail/CVE-2018-16840
USN-3805-1 https://usn.ubuntu.com/3805-1/
No exploits are available.
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2018-16840.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: AV:N/AC:L/Au:N/C:P/I:P/A:P Found at https://nvd.nist.gov/vuln/detail/CVE-2018-16840
Exploitability (E) Access Vector (AV) Access Complexity (AC) Authentication (Au) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

high

functional

unproven

proof_of_concept

not_defined

local

adjacent_network

network

high

medium

low

multiple

single

none

none

partial

complete

none

partial

complete

none

partial

complete
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2018-16840
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.54096
EPSS Score 0.00316
Published At Aug. 16, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-31T08:35:54.278990+00:00 Ubuntu USN Importer Import https://usn.ubuntu.com/3805-1/ 37.0.0