CVE-2018-20200: squareup okhttp Improper Certificate Validation
Vulnerability summary
CVE-2018-20200 is a medium (CVSS 5.9) Improper Certificate Validation vulnerability in squareup okhttp. EPSS estimates a 2.48% chance of exploitation in the next 30 days, higher than 84.6% of scored vulnerabilities. 1 public exploit is recorded.
Not severe (CVSS 5.9, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Timeline
- 18-04-2019PublishedVulnerability first disclosed.
- 05-08-2024Last modifiedVulnerability information updated.
Description
CertificatePinner.java in OkHttp 3.x through 3.12.0 allows man-in-the-middle attackers to bypass certificate pinning by changing SSLContext and the boolean values while hooking the application. NOTE: This id is disputed because some parties don't consider this is a vulnerability. Their rationale can be found in https://github.com/square/okhttp/issues/4967
CVSS metrics
3 scores · 2 sources · 2 versions- OSV · DebianEcosystem advisory · calculated5.9MediumCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
2.48%
Chance of exploitation in the next 30 days
Percentile
85%
Versus all other CVEs
30-day change
No change 0.00 pp
From 2.48% on 05-10-2026
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 (cxsecurity.com)
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.
Debian1 product
- libokhttp-javaAll versions (No fix recorded)
Squareup1 product
- okhttp≥ 3.0.0, ≤ 3.12.0
2 vendors · 2 products
References
16 links- github.com/square/okhttp/issues/4967X Refsource MISC
