Vulnerability in aaPanel BillionMail

[ Why it matters ]Priority signals

• Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

BillionMail through 4.9 contains a hard-coded cryptographic key vulnerability that allows unauthenticated attackers to forge unsubscribe and subscribe-confirm JWTs by computing the key from shipped configuration constants. Attackers can submit forged tokens to /api/unsubscribe, /api/unsubscribe_new, or /api/subscribe/confirm to deactivate any contact or force confirmed subscriptions.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

• github.com/aaPanel/BillionMail
• github.com/aaPanel/BillionMail/blob/v4.9/core/internal/service/batch_mail/jwt.go
• github.com/aaPanel/BillionMail/blob/v4.9/core/manifest/config/config.yaml
• hackmd.io/@hieuPenguinnn/billionmail-unsubscribe-subscribe-jwt-deterministic-secret-for…
• www.vulncheck.com/advisories/billionmail-through-4.9-forgeable-jwts-via-default-signing…