CVE-2019-25569 RealTerm Serial Terminal 2.0.0.70 SEH Overflow Crash

Medium 6.9 Published 21 Mar 2026 Updated 23 Mar 2026

Local attackers can crash RealTerm Serial Terminal by triggering a stack-based buffer overflow via crafted input in the Echo Port field.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2019-25569?

CVE-2019-25569 is a medium-severity memory corruption vulnerability in RealTerm: Serial Terminal, published on 21 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

RealTerm Serial Terminal 2.0.0.70 contains a stack-based buffer overflow vulnerability in the Echo Port field that allows local attackers to crash the application by triggering a structured exception handler (SEH) chain corruption. Attackers can craft a malicious input string with 268 bytes of padding followed by SEH overwrite values and paste it into the Port field to cause denial of service.

Weakness: CWE-787

Which versions are affected by CVE-2019-25569?

It affects 1 product.

Products include Crun Realterm.

How do I fix CVE-2019-25569?

No fix has been published for CVE-2019-25569 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2019-25569 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2019-25569 exists.

Sources

Also known as GHSA-qm4h-vmrq-638h.