As announced by Go upstream on 2019-10-17: Invalid DSA public keys can cause a panic in dsa.Verify. In particular, using crypto/x509.Verify on a crafted X.509 certificate chain can lead to a panic, even if the certificates don’t chain to a trusted root. The chain can be delivered via a crypto/tls connection to a client, or to a server that accepts and verifies client certificates. net/http clients can be made to crash by an HTTPS server, while net/http servers that accept client certificates will recover the panic and are unaffected.

Moreover, an application might crash invoking crypto/x509.(CertificateRequest) CheckSignature on an X.509 certificate request, parsing a golang.org/x/crypto/openpgp Entity, or during a golang.org/x/crypto/otr conversation. Finally, a golang.org/x/crypto/ssh client can panic due to a malformed host key, while a server could panic if either PublicKeyCallback accepts a malformed public key, or if IsUserAuthority accepts a certificate with a malformed public key.

Upstream bug: https://github.com/golang/go/issues/34960

An issue was found in Arista EOS. Specific malformed ARP packets can impact the software forwarding of VxLAN packets. This issue is found in Arista’s EOS VxLAN code, which can allow attackers to crash the VxlanSwFwd agent. This affects EOS 4.21.8M and below releases in the 4.21.x train, 4.22.3M and below releases in the 4.22.x train, 4.23.1F and below releases in the 4.23.x train, and all releases in 4.15, 4.16, 4.17, 4.18, 4.19, 4.20 code train.