Short Name |
DNS:REQUEST:DNS-INT-UNDERFLOW |
---|---|
Severity |
Minor |
Recommended |
Yes |
Recommended Action |
Drop |
Category |
DNS |
Keywords |
DNSmasq answer_auth and answer_request Integer Underflow |
Release Date |
2017/10/24 |
Update Number |
3000 |
Supported Platforms |
idp-4.0+, isg-3.0+, j-series-9.5+, mx-11.4+, srx-12.1+, srx-branch-12.1+, vmx-17.4+, vsrx-12.1+, vsrx3bsd-18.2+ |
An integer underflow vulnerability has been reported in dnsmasq. A remote, unauthenticated attacker can exploit this vulnerability by sending a large UDP packet to the target system. Successful exploitation results in termination of the dnsmasq process.
In dnsmasq before 2.78, if the DNS packet size does not match the expected size, the size parameter in a memset call gets a negative value. As it is an unsigned value, memset ends up writing up to 0xffffffff zero's (0xffffffffffffffff in 64 bit platforms), making dnsmasq crash.