Solstice::Session: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
CVE-2026-5085 is a critical-severity use of cryptographically weak pseudo-random number generator (PRNG) vulnerability in Solstice::Session from Mcrawfor, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Solstice::Session versions: 1440 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 0.34% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Solstice::Session you run against the affected versions below, and install the vendor's latest release.
- 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 |
|---|---|---|---|
| MCRAWFOR | Solstice::Session | 1440 and earlier | Not stated |
| Mcrawfor | Solstice | \ | Not stated |
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
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by CISA (ADP).
Official description
Solstice::Session versions through 1440 for Perl generates session ids insecurely. The _generateSessionID method returns an MD5 digest seeded by the epoch time, a random hash reference, a call to the built-in rand() function and the process id. The same method is used in the _generateID method in Solstice::Subsession, which is part of the same distribution. The epoch time may be guessed, if it is not leaked in the HTTP Date header. Stringified hash refences will contain predictable content. The built-in rand() function is seeded by 16-bits and is unsuitable for security purposes. The process id comes from a small set of numbers. Predictable session ids could allow an attacker to gain access to systems.
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: partial).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- security.metacpan.org/docs/guides/random-data-for-security.htmlThird Party Advisory
Other references
Recent Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) vulnerabilities
- 9.8 Critical severity
- 7.5 High severity
- 9.1 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.1 Critical severity
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