WebAuthn assertion replay permits second-factor bypass in Psono Server
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 7.2.4
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
Psono Server (Community and Enterprise editions) is affected, allowing an attacker who already knows a user's password and has captured one valid WebAuthn login response to reuse it and bypass the second-factor check. This could let the attacker gain access to the user's account without possessing their WebAuthn security key.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original description
Psono Server CE & EE versions 3.1.0 through 7.2.3 did not consume a stored WebAuthn challenge after assertion verification. An unauthenticated remote attacker who possessed the user's password and one captured valid WebAuthn assertion could replay that assertion with separate login tokens while the stored challenge remained unchanged, bypassing the WebAuthn second factor. The attack required capture of a valid assertion and did not itself disclose plaintext secrets.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- esaqa GmbH Psono
From 3.1.0 · fixed in 7.2.4