Information disclosure in Sensiolabs Symfony
CVE-2021-21424
Symfony is a PHP framework for web and console applications and a set of reusable PHP components. The ability to enumerate users was possible without relevant permissions due to different handling depending on whether the user existed or not when attempting to use the switch users functionality. We now ensure that 403s are returned whether the user exists or not if a user cannot switch to a user or if the user does not exist. The patch for this issue is available for branch 3.4.
Vulnerability class: Information Disclosure
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.017 (76.5th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 76th percentile — 76.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.017 · newest: 0.017 · change: 0.000
Affected products
- Sensiolabs Symfony
- Symfony — versions >= 2.8.0, < 3.4.48, >= 4.0.0, < 4.4.23, >= 5.0.0, < 5.2.8
- Fedoraproject Fedora — versions 33, 34
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/symfony/symfony/security/advisories/GHSA-5pv8-ppvj-4h68 (Patch, Third Party Advisory)
- github.com/symfony/symfony/commit/2a581d22cc621b33d5464ed65c4bc2057f72f011 (Patch, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.debian.org/debian-lts-announce/2023/07/msg00014.html (mailing-list)
Frequently asked questions
- What is CVE-2021-21424?
- CVE-2021-21424 is a medium-severity vulnerability in Sensiolabs Symfony, classified under Information Disclosure. CVSS score: 5.3/10. Published 2021-05-13.
- How severe is CVE-2021-21424?
- Medium severity. CVSS v3 base score is 5.3 out of 10.
- Is CVE-2021-21424 known to be exploited?
- 5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.