DSA-4697: -1 gnutls28 -- security update
A flaw was reported in the TLS session ticket key construction in GnuTLS, a library implementing the TLS and SSL protocols. The flaw caused the TLS server to not securely construct a session ticket encryption key considering the application supplied secret, allowing a man-in-the-middle attacker to bypass authentication in TLS 1.3 and recover previous conversations in TLS 1.2.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
gnutls28to a version that resolves this vulnerability.Patch DSA-4697-1
Event History
Frequently Asked Questions
Which deployments are exposed to this issue?
TLS servers using the affected GnuTLS library and session tickets are exposed. The provided information does not identify specific applications or configurations beyond use of TLS session tickets.
What capabilities does an attacker need?
An attacker needs to be positioned as a man in the middle of the TLS connection. Under that condition, they may bypass authentication in TLS 1.3 and recover previous conversations in TLS 1.2.
Is a default configuration known to be affected?
The available information does not state whether session tickets are enabled by default in affected GnuTLS-based applications. Exposure depends on a TLS server using the vulnerable session ticket key construction.