CVE-2020-7065: mb_strtolower (UTF-32LE): stack-buffer-overflow at php_unicode_tolower_full
Vulnerability summary
CVE-2020-7065 is a high (CVSS 8.8) Stack-based Buffer Overflow vulnerability in canonical ubuntu_linux. EPSS estimates a 4.88% chance of exploitation in the next 30 days, higher than 92% of scored vulnerabilities. 1 public exploit is recorded.
Public exploit (reference, Date unknown)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 6 · Related 2Timeline
- 01-04-2020PublishedVulnerability first disclosed.
- 17-09-2024Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
6 scores · 5 sources · 2 versions- CVE.orgCNA7.4HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:HDiffers
- OSV · UbuntuEcosystem advisory · calculated7.4HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:HDiffers
- OSV · DebianEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- OSV · AlpineEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS trend
Probability
4.88%
Chance of exploitation in the next 30 days
Percentile
92%
Versus all other CVEs
30-day change
No change 0.00 pp
From 4.88% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
1 foundExploit Reference (bugs.php.net)
Maturity: unknown
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian2 products
- php7.4< 7.4.5-1
- debian_linuxEOL10.0
Alpine1 product
- php7< 7.3.16-r0
Canonical1 product
- ubuntu_linuxEOL12.04 | 14.04 | 16.04 | 18.04 | 19.10 | 20.04
Php1 product
- php≥ 7.3.0, < 7.3.16 | ≥ 7.4.0, < 7.4.4
Php group1 product
- php≥ 7.3.x, < 7.3.16 | ≥ 7.4.x, < 7.4.4
Tenable1 product
- tenable.sc< 5.19.0
Ubuntu1 product
- php7.4< 7.4.3-4ubuntu1.1
7 vendors · 8 products
References
15 links
- git.php.netREPORT