CVE-2021-21706: php_group php Path Traversal: '../filedir'
CVSS: 6.5v3.1MediumModified
AliasesUBUNTU-CVE-2021-21706
Published 04-10-2021Last modified 16-09-2024
Vulnerability summary
CVE-2021-21706 is a medium (CVSS 6.5) Path Traversal: '../filedir' vulnerability in php_group php. EPSS estimates a 1.44% chance of exploitation in the next 30 days, higher than 72.7% of scored vulnerabilities.
CVSS score
6.5/10
010
Medium · v3.1 (NVD)EPSS score
1.44%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 4 · Related 4Timeline
- 04-10-2021PublishedVulnerability first disclosed.
- 16-09-2024Last modifiedVulnerability information updated.
Description
In PHP versions 7.3.x below 7.3.31, 7.4.x below 7.4.24 and 8.0.x below 8.0.11, in Microsoft Windows environment, ZipArchive::extractTo may be tricked into writing a file outside target directory when extracting a ZIP file, thus potentially causing files to be created or overwritten, subject to OS permissions.
CVSS metrics
4 scores · 3 sources · 2 versionsMedium 6.5Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:NSources3 sources · 5.3–6.5
- CVE.orgCNA5.3MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:NDiffers
- OSV · UbuntuEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:NDiffers
Medium 4.3Preferred score · NVD (NIST)
AV:N/AC:M/Au:N/C:N/I:P/A:NSourcesSingle source
EPSS trend
Probability
1.44%
Chance of exploitation in the next 30 days
Percentile
73%
Versus all other CVEs
30-day change
0.00 pp
From 1.44% on 19-09-2026
19-09-202619-10-2026
EPSS score1.44%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-24Path Traversal: '../filedir'The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize "../" sequences that can resolve to a location that is outside of that directory.
- CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Affected systems
Php1 product
- php≥ 7.3.0, < 7.3.31 | ≥ 7.4.0, < 7.4.24 | ≥ 8.0.0, < 8.0.11
Php_group1 product
- php≥ 7.3.x, < 7.3.31 | ≥ 7.4.x, < 7.4.24 | ≥ 8.0.X, < 8.0.11
Ubuntu1 product
- php8.1< 8.1.0-1
3 vendors · 3 products