JVN#77718330
Vulnerability in the jBCrypt key stretching process
Overview
jBCrypt contains an integer overflow vulnerability in the key stretching process.
Products Affected
- jBCrypt-0.3 and earlier
Description
jBCrypt is a Java implementation to compute password hashes. jBCrypt contains an integer overflow vulnerability in the key stretching process. An integer overflow occurs when the parameter for the repetition count is set to the maximum value allowed, 31.
Impact
When the hash value for a password is obtained by a remote attacker, a brute force attack may be used to easily recover the password.
Solution
Update the Software
Update to the latest version according to the information provided by the developer.
Vendor Status
| Vendor | Link |
| mindrot.org | jBCrypt-0.4 |
References
-
OpenSSH: Bugs
[Bug 2097] if gensalt's log_rounds parameter is set to 31 it does 0 (ZERO) rounds!
JPCERT/CC Addendum
Vulnerability Analysis by JPCERT/CC
Analyzed on 2015.02.27 (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 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 considerable informational disclosure. Access to some system files is possible, but the attacker does not have control over what is obtained, or the scope of the loss is constrained. |
| Integrity Impact(I) | None (N) | Partial (P) | Complete (C) | There is no impact to the integrity of the system. |
| Availability Impact(A) | None (N) | Partial (P) | Complete (C) | There is no impact to the availability of the system. |
Base Score:2.6
Comment
This analysis assumes that a remote attacker obtains the hash value through the network.
Credit
Norito AGETSUMA reported this vulnerability to IPA.
JPCERT/CC coordinated with the developer under Information Security Early Warning Partnership.
Other Information
| JPCERT Alert | |
| JPCERT Reports | |
| CERT Advisory |
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| CPNI Advisory |
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| TRnotes |
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| CVE |
CVE-2015-0886 |
| JVN iPedia |
JVNDB-2015-000033 |