Medium

Apple App Store Server Python Library: SignedDataVerifier accepts stale OCSP GOOD responses and can bypass certificate revocation checks

  • Disclosed: 13.07.2026
  • Updated: 11.10.2026 14:18

Summary

SignedDataVerifier attempts to perform online revocation checking when enable_online_checks=True, but its OCSP validation logic accepts stale GOOD responses as valid indefinitely. In appstoreserverlibrary/signed_data_verifier.py, _ChainVerifier.check_ocsp_status() verifies the OCSP response signature and CertID match, but never validates the freshness window carried by producedAt, thisUpdate, or nextUpdate.

As a result, a previously valid signed OCSP GOOD response can be replayed after it is expired, and the library will still treat the certificate as good. If an App Store signing certificate or intermediate is ever revoked, applications using this library with online checks enabled can continue accepting JWS objects signed with the revoked key as long as a stale signed OCSP response is replayed.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Python (PyPI) app-store-server-library >= 0.2.0, < 3.1.2 3.1.2

References

CVSS score -
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Weakness (CWE)
CWE-295, CWE-299
Platform
Python (PyPI)
Package
app-store-server-library
Disclosed
13.07.2026
Updated
11.10.2026 14:18

Sources and licenses

OSV / GitHub Advisory Database - GHSA-8f6j-263m-g72x - CC BY 4.0

Vulnerability history: app-store-server-library

All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.

This is the only known vulnerability of this package.

Know which vulnerabilities affect your application

With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.

Connect your application
DockRay newsletter

Application security in your inbox

Important vulnerabilities, actionable guidance and practical advice for your applications. Choose your technologies and follow what matters to your project.

  • A daily digest of new vulnerabilities, critical ones included.
  • Notifications about important updates.
  • Practical advice on application security and monitoring.

Leave empty to receive updates for every technology.

Free to subscribe. Unsubscribe with one click in any email.