CVSS 6.5 · Medium EPSS 0,34%
Kerentanan Use After Free pada nlnetlabs unbound. Skor CVSS 3.1 6.5 (Medium) menurut nlnetlabs.nl.
NLnet Labs Unbound 1.22.0 up to and including 1.26.1, has a use-after-free vulnerability when compiled for DNS-over-QUIC support with '--with-libngtcp2'. Each DoQ stream owns an output buffer that holds the DNS response. ngtcp2's retransmission buffer keeps a shallow pointer into the output buffer for as long as a STREAM frame may be resent. On a client RESET_STREAM, the output buffer is freed but ngtcp2 still holds the matching retransmission entries. The next PTO timeout makes ngtcp2 re-encode the STREAM frame and copy from the freed buffer. A malicious actor that can query Unbound over DoQ and that withholds ACKs, sends RESET_STREAM, and waits for PTO, reaches this use-after-free with no privilege. This leads to retransmissions against freed memory and eventually an abnormal server exit under a 20-query spray.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L
· uraikan di kalkulator | Vendor | Produk | Versi terdampak |
|---|---|---|
| nlnetlabs | unbound | Versi 1.22.0 hingga sebelum 1.26.1 |