CVE-2020-12283 is a medium-severity (CVSS 6.1) Open Redirect vulnerability in github.com/sourcegraph/sourcegraph. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether CVE-2020-12283 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Open redirect vulnerability in Sourcegraph
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2020-12283 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 0 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/sourcegraph/sourcegraph🐹github.com/sourcegraph/sourcegraphReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Impact
An open redirect vulnerability that allows users to be targeted for phishing attacks has been found in Sourcegraph instances configured with OAuth, OpenID, or SAML authentication enabled. Users targeted by these phishing attacks could have their authentication tokens silently harvested by an attacker.
Specific Go Packages Affected
github.com/sourcegraph/sourcegraph/cmd/frontend/auth
Resolution
Sourcegraph v3.14.4 and v3.15.1 have been released which resolve the vulnerability. (associated change)
Workarounds
Disabling OAuth, OpenID and/or SAML sign-in options until upgraded to the patched versions will secure Sourcegraph / workaround the issue.
Timeline
- Apr 23, 8 AM PST: GitHub Security Lab reported the issue to Sourcegraph.
- Apr 23, 11 PM PST: A Sourcegraph engineer proposed a resolution for the vulnerability. https://github.com/sourcegraph/sourcegraph/pull/10167
- Apr 24, 3 AM PST: The proposed resolution was reviewed, approved, and merged.
- Apr 28, 2 PM PST: Patch releases for 3.14.4 and 3.15.1 were published.
- Apr 29, 10 PM PST: Mitre publicly disclosed CVE-2020-12283.
- Apr 30, 11 AM PST: Sourcegraph issued a GitHub security advisory and notified all affected users.
References
- Mitre: CVE-2020-12283
- GitHub Security Lab: GHSL-2020-085
- detectify's blog post on open redirect vulnerabilities
For more information
If you have any questions or comments about this advisory, please contact us at [email protected] and include CVE-2020-12283 in the title.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/sourcegraph/sourcegraph | all versions | 3.14.4 |
| 🐹Go | github.com/sourcegraph/sourcegraph | ≥ 3.15.0&&< 3.15.1 | 3.15.1 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/sourcegraph/sourcegraph. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/sourcegraph/sourcegraph to 3.14.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-12283 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2020-12283 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2020-12283. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2020-12283 in your dependencies?
O3 detects CVE-2020-12283 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.