IP address leak via image proxy bypass in Zulip Server
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 4.3epss 0.5%
exploitation probability
0.5%top 58% of all CVEs
observed exploitation
nono source reports it
Zulip is an open-source team collaboration tool with topic-based threading that combines email and chat. When displaying messages with embedded remote images, Zulip normally loads the image preview via a go-camo proxy server. However, an attacker who can send messages could include a crafted URL that tricks the server into embedding a remote image reference directly. This could allow the attacker to infer the viewer’s IP address and browser fingerprinting information. This vulnerability is fixed in Zulip Server 5.6. Zulip organizations with image and link previews [disabled](https://zulip.com/help/allow-image-link-previews) are not affected.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Affected products
zulip · zulip