Issue summary: QUIC, when performing automated peer detection, may allow uninitialized stack data to leak into the received address which i…

Issue summary: QUIC, when performing automated peer detection, may allow
uninitialized stack data to leak into the received address which is then used
as the destination for outgoing packets.

Impact summary: Applications using QUIC's automated peer detection mechanism
may receive an invalid address, leading to connection loss and disclosure of
uninitialized stack data to an attacker observing the outgoing network traffic.

CWE: CWE-457 (Use of Uninitialized Variable)

Description: The OpenSSL QUIC stack contains a feature in which, when using an
already connected socket, it will auto-detect the peer address during the SSL
handshake. This feature uses the getpeername() function, passing a buffer of
sufficient length to hold any supported address family, but passes a buffer
length that is only sized such that larger addresses, such as IPv6, cannot be
retrieved. The getpeername() function however, still returns the full address
length, which is accepted as the valid input buffer length, leading to the
address buffer containing uninitialized stack data instead of the actual peer
address. The invalid peer address is then used as destination for the outgoing
packets which leads to a connectivity breakage and a leakage of the
uninitialized stack data to passive network observers.

FIPS impact: no
The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this CVE as
the affected protocol is not implemented in the FIPS module.