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Vulnerability details: VCID-dwyw-64yp-vygf
Vulnerability ID VCID-dwyw-64yp-vygf
Aliases CVE-2019-18840
Summary In wolfSSL 4.1.0 through 4.2.0c, there are missing sanity checks of memory accesses in parsing ASN.1 certificate data while handshaking. Specifically, there is a one-byte heap-based buffer overflow inside the DecodedCert structure in GetName in wolfcrypt/src/asn.c because the domain name location index is mishandled. Because a pointer is overwritten, there is an invalid free.
Status Published
Exploitability None
Weighted Severity None
Risk None
Affected and Fixed Packages Package Details
Weaknesses (1)
CWE-787 Out-of-bounds Write
System Score Found at
epss 0.00411 https://api.first.org/data/v1/epss?cve=CVE-2019-18840
epss 0.00411 https://api.first.org/data/v1/epss?cve=CVE-2019-18840
epss 0.00411 https://api.first.org/data/v1/epss?cve=CVE-2019-18840
epss 0.00411 https://api.first.org/data/v1/epss?cve=CVE-2019-18840
epss 0.00411 https://api.first.org/data/v1/epss?cve=CVE-2019-18840
epss 0.00411 https://api.first.org/data/v1/epss?cve=CVE-2019-18840
epss 0.00411 https://api.first.org/data/v1/epss?cve=CVE-2019-18840
epss 0.00411 https://api.first.org/data/v1/epss?cve=CVE-2019-18840
epss 0.00411 https://api.first.org/data/v1/epss?cve=CVE-2019-18840
epss 0.00411 https://api.first.org/data/v1/epss?cve=CVE-2019-18840
epss 0.00411 https://api.first.org/data/v1/epss?cve=CVE-2019-18840
epss 0.00411 https://api.first.org/data/v1/epss?cve=CVE-2019-18840
epss 0.00411 https://api.first.org/data/v1/epss?cve=CVE-2019-18840
epss 0.00411 https://api.first.org/data/v1/epss?cve=CVE-2019-18840
epss 0.00411 https://api.first.org/data/v1/epss?cve=CVE-2019-18840
cvssv2 5.0 https://nvd.nist.gov/vuln/detail/CVE-2019-18840
cvssv3 7.5 https://nvd.nist.gov/vuln/detail/CVE-2019-18840
cvssv3.1 7.5 https://nvd.nist.gov/vuln/detail/CVE-2019-18840
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2019-18840
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-18840
https://github.com/wolfSSL/wolfssl/issues/2555
cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*
CVE-2019-18840 https://nvd.nist.gov/vuln/detail/CVE-2019-18840
No exploits are available.
Vector: AV:N/AC:L/Au:N/C:N/I:N/A:P Found at https://nvd.nist.gov/vuln/detail/CVE-2019-18840
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:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2019-18840
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2019-18840
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 0.61262
EPSS Score 0.00411
Published At April 1, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-04-01T16:33:43.670547+00:00 Debian Oval Importer Import https://www.debian.org/security/oval/oval-definitions-bullseye.xml.bz2 38.0.0