CVE-2020-5290: session fixation in rCTF

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2020-04-01 · updated 2026-06-17
Weakness: CWE-384

Description

In RedpwnCTF before version 2.3, there is a session fixation vulnerability in exploitable through the `#token=$ssid` hash when making a request to the `/verify` endpoint. An attacker team could potentially steal flags by, for example, exploiting a stored XSS payload in a CTF challenge so that victim teams who solve the challenge are unknowingly (and against their will) signed into the attacker team's account. Then, the attacker can gain points / value off the backs of the victims. This is patched in version 2.3.

Affected products

redpwn rctf: before 2.3 — fixed in 2.3

How to fix

Upgrade to a fixed version: redpwn rctf 2.3. Check the vendor advisory for mitigations.

References

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