CVE-2017-11424

high

Published 2017-08-24 · Modified 2023-11-08

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CVSS v3

7.5

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CVSS v4 NEW

—

not yet in upstream

VIR risk

7.5

Description

In PyJWT 1.5.0 and below the `invalid_strings` check in `HMACAlgorithm.prepare_key` does not account for all PEM encoded public keys. Specifically, the PKCS1 PEM encoded format would be allowed because it is prefaced with the string `-----BEGIN RSA PUBLIC KEY-----` which is not accounted for. This enables symmetric/asymmetric key confusion attacks against users using the PKCS1 PEM encoded public keys, which would allow an attacker to craft JWTs from scratch.

Predictions

Exploit likelihood

83%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

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OS impact

OS	Version	Status	Fixed in
debian	8.0	affected
debian	9.0	affected
debian	bookworm	fixed	`1.4.2-1.1`
debian	bullseye	fixed	`1.4.2-1.1`
debian	forky	fixed	`1.4.2-1.1`
debian	sid	fixed	`1.4.2-1.1`
debian	trixie	fixed	`1.4.2-1.1`

Package impact

Ecosystem	Package	Vulnerable	Fixed
PyPI	pyjwt	`<1.5.1`	`1.5.1`

Application impact

Vendor	Product	Versions	Fixed
pyjwt_project	pyjwt	`{"endIncluding":"1.5.0"}`

References

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.