#VU52596 Predictable from Observable State in systemd - CVE-2020-13529

Vulnerability identifier: #VU52596

Vulnerability risk: Low

CVSSv4.0: 1.3 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2020-13529

CWE-ID: CWE-341

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
systemd
Server applications / Other server solutions

Vendor: Freedesktop.org

Description

The vulnerability allows a remote attacker to reconfigure the target device.

The vulnerability exists due to usage of predictable Transactions Identifiers when processing DHCP ACK packets. A remote attacker on the same network can forge the FORCERENEW and DHCP ACK packets to reconfigure the systemd’s DHCP client settings.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

systemd: 216 - 247.6

---

External links
https://www.talosintelligence.com/vulnerability_reports/TALOS-2020-1142

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

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