What this actually is.
Technical background, root cause, and affected surface.
Netatalk 1.5.0 through 4.2.2 uses a broken cryptographic algorithm in the DHCAST128 UAM, which allows a remote attacker to obtain authentication credentials or impersonate a user via cryptanalytic attack.
- Vendor
- Netatalk
- Product
- Netatalk
- Severity
- High
- CVSS Score
- 7.4
- Status
- Published
- CWE
- CWE-327: Use of a Broken or Risky Cryptographic Algorithm
- Vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
From one request
to root shell.
Reproduced in a sandboxed environment. Requires only LAN or WiFi adjacency.
The bug, and the fix.
etc/uams/uams_dhcast128.c: DHCAST128 authentication handshake uses cryptographically weak algorithm for key exchange and credential protection
Root cause: DHCAST128 relies on a deprecated, cryptographically weak algorithm that does not provide adequate protection against modern cryptanalytic techniques
When does this fire?
All conditions must be true for the exploit to succeed.
AFP client authenticates using DHCAST128 UAM; attacker captures the authentication exchange via network sniffing
What an attacker does to you.
Post-exploitation outcomes mapped to CVSS impact metrics.
Recovery of AFP user credentials via offline cryptanalysis; authentication impersonation
C:H · I:H · A:N
CWE-327: Use of a Broken or Risky Cryptographic Algorithm
Fix it. In this order.
A runbook, not a checklist. Sequence matters — assume compromise before you act.
Upgrade to Netatalk 4.4.3 and disable DHCAST128 UAM. Use DHX2 (Diffie-Hellman Exchange 2) which uses cryptographically sound algorithms.
disclose@securin.ioVendors moved in days.
Attackers in hours.
Reconstructed from vendor advisories, CISA bulletins, and Securin research records.
Vendor notified
Netatalk 4.4.3 patch released
CVE published to MITRE
Disclosed 60 days after discovery
Cite, verify, go deeper.
Primary sources — NVD, CISA KEV, and machine-readable IoC feed.