Apache Druid: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
CVE-2025-59390 is a critical-severity use of cryptographically weak pseudo-random number generator (PRNG) vulnerability in Apache Druid from Apache, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Apache Druid versions: 34.0.0 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.7% chance of exploitation within 30 days, higher than 54% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Druid to 35.0.0 or a later version.
- Read the advisory on lists.apache.org for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apache | Apache Druid | 34.0.0 and earlier | Not stated |
| Apache | Druid | before 35.0.0 | 35.0.0 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CISA (ADP).
Official description
Apache Druid’s Kerberos authenticator uses a weak fallback secret when the `druid.auth.authenticator.kerberos.cookieSignatureSecret` configuration is not explicitly set. In this case, the secret is generated using `ThreadLocalRandom`, which is not a crypto-graphically secure random number generator. This may allow an attacker to predict or brute force the secret used to sign authentication cookies, potentially enabling token forgery or authentication bypass. Additionally, each process generates its own fallback secret, resulting in inconsistent secrets across nodes. This causes authentication failures in distributed or multi-broker deployments, effectively leading to a incorrectly configured clusters. Users are advised to configure a strong `druid.auth.authenticator.kerberos.cookieSignatureSecret` This issue affects Apache Druid: through 34.0.0. Users are recommended to upgrade to version 35.0.0, which fixes the issue making it mandatory to set `druid.auth.authenticator.kerberos.cookieSignatureSecret` when using the Kerberos authenticator. Services will fail to come up if the secret is not set.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG's algorithm is not cryptographically strong.
How developers prevent this class of flaw
- Use functions or hardware which use a hardware-based random number generation for all crypto. This is the recommended solution. Use CyptGenRandom on Windows, or hw_rand() on Linux.
More Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) vulnerabilities (CWE-338)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- openwall.com/lists/oss-security/2025/11/26/1Mailing List, Third Party Advisory
Other vulnerabilities in Apache Druid
- 9.8 Critical severity
Recent Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) vulnerabilities
- 7.4 High severity
- 9.1 Critical severity
- 7.5 High severity
- 8.6 High severity
- 9.3 Critical severity
- 9.8 Critical severity
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