#VU93491 Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) in DNS library in Go - CVE-2019-19794

Vulnerability identifier: #VU93491

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-19794

CWE-ID: CWE-338

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
DNS library in Go
Universal components / Libraries / Libraries used by multiple products

Vendor: miekg

Description

The vulnerability allows a remote attacker to poison DNS cache.

The vulnerability exists due to usage of predictable random numbers for TXID. A remote attacker can forge DNS responses.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

DNS library in Go: before 1.1.25

---

External links
https://github.com/coredns/coredns/issues/3519
https://github.com/coredns/coredns/issues/3547
https://github.com/miekg/dns/compare/v1.1.24...v1.1.25
https://github.com/miekg/dns/issues/1043
https://github.com/miekg/dns/pull/1044

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.