CVE-2020-7065 | mb_strtolower (UTF-32LE): stack-buffer-overflow at php_unicode_tolower_full

Exp

In PHP versions 7.3.x below 7.3.16 and 7.4.x below 7.4.4, while using mb_strtolower() function with UTF-32LE encoding, certain invalid strings could cause PHP to overwrite stack-allocated buffer. This could lead to memory corruption, crashes and potentially code execution.

Published: 2020-04-01 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-7065 is rated High Exploit Risk (75/100): CVSS High severity, with medium exploitation likelihood (EPSS 5.02%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2020-7065

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2020-7065

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-25 5.98% 5.02% -0.96%
2 2026-03-04 7.27% 5.98% -1.29%
3 2026-03-01 — 7.27% —

Full EPSS history (44 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-7065

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.4 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 5.2 [email protected]
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2020-7065

OS Trackers for CVE-2020-7065

vendor priority summary link
alpine high CVE-2020-7065: 1 source package rows (php7); 1 state rows across 1 repos (edge-community); fixed 1, open 0. https://security.alpinelinux.org/vuln/CVE-2020-7065
debian not yet assigned CVE-2020-7065 not yet assigned priority: Debian including 1 source packages (php7.4), 1 status rows across 1 suites (bullseye): resolved 1. https://security-tracker.debian.org/tracker/CVE-2020-7065
gentoo high CVE-2020-7065: 1 GLSA(s) (202003-57), 1 atom(s) (dev-lang/php); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2020-7065
redhat medium — https://access.redhat.com/security/cve/CVE-2020-7065
ubuntu medium CVE-2020-7065 medium priority: Ubuntu including 5 source packages (php5, php7.0, php7.2, php7.3, php7.4), 30 status rows across 6 suites (bionic, eoan, focal, trusty, upstream, xenial): DNE 20, needs-triage 4, not-affected 3, released 3. https://ubuntu.com/security/CVE-2020-7065

Affected software / configurations for CVE-2020-7065

Vendor Product Version Raw CPE
php php >= 7.3.0, < 7.3.16 cpe:2.3:a:php:php:*:*:*:*:*:*:*:*
php php >= 7.4.0, < 7.4.4 cpe:2.3:a:php:php:*:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
canonical ubuntu_linux 12.04 cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 19.10 cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*
canonical ubuntu_linux 20.04 cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*
tenable tenable.sc < 5.19.0 cpe:2.3:a:tenable:tenable.sc:*:*:*:*:*:*:*:*

References for CVE-2020-7065

URL Tags
https://bugs.php.net/bug.php?id=79371 Exploit Issue Tracking Patch Vendor Advisory
https://security.netapp.com/advisory/ntap-20200403-0001/ Third Party Advisory
https://usn.ubuntu.com/4330-1/ Third Party Advisory
https://usn.ubuntu.com/4330-2/ Third Party Advisory
https://www.debian.org/security/2020/dsa-4719 Third Party Advisory
https://www.oracle.com/security-alerts/cpuoct2021.html Patch Third Party Advisory
https://www.php.net/ChangeLog-7.php#7.4.4 Release Notes Vendor Advisory
https://www.tenable.com/security/tns-2021-14 Third Party Advisory
cvelogic Threat Intelligence