Authorization Flaw in jupyterhub-kubespawner (CVE-2020-15110)
Summary
Vulnerability in jupyterhub-kubespawner (CVE-2020-15110). Confidential information can be exposed externally. Exploitable via user. Mitigation: upgrade to 0.12.0 or later.
Original description
The description as published by the source.
Impact
What kind of vulnerability is it? Who is impacted?
JupyterHub deployments using:
- KubeSpawner <= 0.11.1 (e.g. zero-to-jupyterhub 0.9.0) and
- enabled named_servers (not default), and
- an Authenticator that allows:
- usernames with hyphens or other characters that require escape (e.g.
user-hyphenoruser@email), and - usernames which may match other usernames up to but not including the escaped character (e.g.
userin the above cases)
- usernames with hyphens or other characters that require escape (e.g.
In this circumstance, certain usernames will be able to craft particular server names which will grant them access to the default server of other users who have matching usernames.
Patches
Has the problem been patched? What versions should users upgrade to?
Patch will be released in kubespawner 0.12 and zero-to-jupyterhub 0.9.1
Workarounds
Is there a way for users to fix or remediate the vulnerability without upgrading?
KubeSpawner
Specify configuration:
for KubeSpawner
from traitlets import default
from kubespawner import KubeSpawner
class PatchedKubeSpawner(KubeSpawner):
@default("pod_name_template")
def _default_pod_name_template(self):
if self.name:
return "jupyter-{username}-{servername}"
else:
return "jupyter-{username}"
@default("pvc_name_template")
def _default_pvc_name_template(self):
if self.name:
return "claim-{username}-{servername}"
else:
return "claim-{username}"
c.JupyterHub…
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2020-15110 has been found in jupyterhub-kubespawner.
Attackers can target a specific entry point like user over the network to misuse the product.
Confidential information can be exposed externally.
What to do: upgrade jupyterhub-kubespawner to 0.12.0 or later.
If unsure, ask your IT team or search "jupyterhub-kubespawner CVE-2020-15110" on the vendor's site.
CVE-2020-15110 (jupyterhub-kubespawner) — CWE-863
Attack vector: remote (network-reachable) / no user interaction
Attack surface: user
Patched: 0.12.0 — apply immediately
Workaround: Is there a way for users to fix or remediate the vulnerability without upgrading?
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Incorrect authorization (CWE-863) exists in jupyterhub-kubespawner. Attackers reach the vulnerable code path via user.
Check the vendor advisory for the affected versions of jupyterhub-kubespawner. Attack surface: user.
Severity: ?. Confidential information can be exposed externally.
Update to 0.12.0.
Workaround: Is there a way for users to fix or remediate the vulnerability without upgrading?
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'jupyterhub-kubespawner' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'jupyterhub-kubespawner' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
jupyterhub-kubespawnerを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
_Is there a way for users to fix or remediate the vulnerability without upgrading?_パッチが適用されるまでの応急処置として、Is there a way for users to fix or remediate the vulnerability without upgrading? を実施。回避策の副作用 (機能低下) を確認した上で。
-
3Apply patch patch
Upgrade jupyterhub-kubespawner to 0.12.0ステージング環境で 0.12.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
4Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com