https://seclists.org/oss-sec/2025/q3/17: Opossum attack / Opportunistic HTTP (RFC 2817) insecu

Published Jul 9, 2025
·
Updated

Affected Software

2 affected components
Apache httpd
Icecast Icecast
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Frequently Asked Questions

1

What is the severity of Opossum attack / Opportunistic HTTP (RFC 2817) vulnerability?

The severity of the Opossum attack vulnerability is significant as it affects the integrity and confidentiality of TLS communication.

2

How does the Opossum attack exploit opportunistic TLS configurations?

The Opossum attack exploits the differences in underlying protocols by manipulating opportunistic TLS to potentially downgrade secure connections.

3

Which software is affected by the Opossum attack / Opportunistic HTTP (RFC 2817) vulnerability?

The Opossum attack impacts servers using Apache httpd and Icecast among others that support opportunistic TLS.

4

How can I mitigate the Opossum attack / Opportunistic HTTP (RFC 2817) vulnerability?

Mitigation can be achieved by configuring servers to disable opportunistic TLS and enforce only implicit TLS connections.

5

What are the potential impacts of the Opossum attack on a server's security?

The potential impacts include exposure to eavesdropping and man-in-the-middle attacks due to weakened TLS configurations.

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