JVN#06120222
F21 JWT fails to verify token signatures
Overview
JWT provided by F21 contains a vulnerability where it fails to verify token signatures.
Products Affected
- JWT versions prior to 2.0
Description
JWT provided by F21 is a PHP library for handling JSON Web Tokens. JWT contains a vulnerability where it fails to verify token signatures.
Impact
Specially crafted tokens may be validated as token data with valid signatures.
Solution
Update the Software
Update to the latest version according to the information provided by the developer.
Vendor Status
| Vendor | Link |
| F21 | F21/jwt |
References
JPCERT/CC Addendum
Vulnerability Analysis by JPCERT/CC
Analyzed on 2015.06.03 (CVSS Base Metrics)
| Measures | Severity | Description | ||
|---|---|---|---|---|
| Access Vector(AV) | Local (L) | Adjacent Network (A) | Network (N) | A vulnerability exploitable with network access means the vulnerable software is bound to the network stack and the attacker does not require local network access or local access. Such a vulnerability is often termed "remotely exploitable". |
| Access Complexity(AC) | High (H) | Medium (M) | Low (L) | Specialized access conditions or extenuating circumstances do not exist. |
| Authentication(Au) | Multiple (M) | Single (S) | None (N) | Authentication is not required to exploit the vulnerability. |
| Confidentiality Impact(C) | None (N) | Partial (P) | Complete (C) | There is no impact to the confidentiality of the system. |
| Integrity Impact(I) | None (N) | Partial (P) | Complete (C) | Modification of some system files or information is possible, but the attacker does not have control over what can be modified, or the scope of what the attacker can affect is limited. |
| Availability Impact(A) | None (N) | Partial (P) | Complete (C) | There is no impact to the availability of the system. |
Base Score:5.0
Credit
Toshiharu Sugiyama of DeNA Co., Ltd. and Shuntaro Maeda reported this vulnerability to IPA.
JPCERT/CC coordinated with the developer under Information Security Early Warning Partnership.
Other Information
| JPCERT Alert |
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| JPCERT Reports |
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| CERT Advisory |
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| CPNI Advisory |
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| TRnotes |
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| CVE |
CVE-2015-2951 |
| JVN iPedia |
JVNDB-2015-000073 |
Update History
- 2015/06/17
- Information under the section "Description" was modified.