CVE-2021-29651Medium· 6.3▾ SunlitJWT leak via Open Redirect in Programmatic access
▾ Sunlit zone — Low / medium · no exploitation signal
impact 34.7 · likelihood 0.1 · exploitation 0
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Exploit-prediction probability, daily snapshots since Jul 9.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via OSV
Last analysed / modified upstream
0.7%
Using programmatic access on protected sites, one can get a signed login URL with pomerium_redirect_uri set to an arbitrary URL. Then, if the user has already logged into Pomerium, they will be redirected to the specified pomerium_redirect_uri with a JWT attached. This allows an outside attacker to get a signed login URL that, upon visiting it, will redirect a victim to the attacker’s site. This creates an issue of Open Redirect and, more seriously, JWT leakage.
With a leaked JWT, the attacker will be able to unveil the victim’s identity (.e.g. email address) by supplying the JWT to the authenticate service or verify.pomerium.com. In addition, if an application integrating Pomerium only verifies the iss claim and others but not the aud claim, the attacker will be able to access it as the victim.
github.com/pomerium/pomerium/proxy
Patched in Pomerium v0.13.4
If you have any questions or comments about this advisory
github.com/pomerium/pomerium < 0.13.4Upgrade to a patched release:
github.com/pomerium/pomerium 0.13.4Connected by shared product, vendor, weakness, or advisory.
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CVE-2021-29652Medium· 6.1pomerium_signature is not verified in middleware in github.com/pomerium/pomerium
CVE-2026-50285High· 7.5Pomerium is an identity and context-aware access proxy