Unsalted HMAC-SHA1 password hashes in CallBackery for Perl
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA.
Summary
CallBackery versions before 0.62.0 for Perl store user passwords as unsalted HMAC-SHA1 hashes. Passwords are hashed with a single fast SHA-1 HMAC that has no key and no salt, so equal passwords produce equal hashes and no work factor slows guessing. An attacker who obtains the user table can recover passwords by fast offline guessing, with no authentication or user interaction needed to read the table.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
CallBackery versions before 0.62.0 for Perl store user passwords as unsalted HMAC-SHA1 hashes. Passwords are hashed with hmac_sha1_sum() from Mojo::Util with no key, a single fast SHA-1 HMAC. There is no salt, so equal passwords give equal hashes, and no work factor slows down guessing. An attacker who obtains the user table can recover passwords by fast offline guessing.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | CallBackery | before 0.62.0 | 0.62.0 | Patch available | CNA |
- CallBackery Vendor— Affected before 0.62.0 Fixed in 0.62.0 Patch available CNA
Remediation
CallBackery users should upgrade to version 0.62.0 or later, which fixes the flaw.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA CallBackery Fixed in 0.62.0
Timeline
- 2026-10-30 Threatist record created from CVE-2026-13576
- 2026-10-30 Alias added: GHSA-6v4f-gp6f-2gvj
- 2026-11-06 CVSS score added · CISA ADP
- 2026-11-06 CISA SSVC decision points changed
References
Sources
- CVE-2026-13576 · CVE Program
- CVE-2026-13576 · NVD
- FIRST EPSS
- GHSA-6v4f-gp6f-2gvj · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences