PoC Index

CVE-2017-11424

HIGH 7.5EPSS 1.8%

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.

CVSS v3.0
7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS v3.0
7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS v2.0
5.0 MEDIUMAV:N/AC:L/Au:N/C:N/I:P/A:N
EPSS
1.80% chance of exploitation in the next 30 days, 77th percentile
Published
2017-08-24
Updated
2024-08-05

Proof-of-concept exploits (1)

References

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