Plack-Middleware-Session before version 0.35 for Perl generates session ids insecurely.
The default session id generator returns a SHA-1 hash seeded with the built-in rand function, the epoch time, and the PID. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage.
Predicable session ids could allow an attacker to gain access to systems.
{
"cna_assigner": "CPANSec",
"cwe_ids": [
"CWE-338",
"CWE-340"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40923.json"
}{
"extracted_events": [
{
"range": [
{
"introduced": "0.01"
},
{
"fixed": "0.35"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
},
{
"range": [
{
"fixed": "1fbfbb355e34e7f4b3906f66cf958cedadd2b9be"
}
],
"source": "REFERENCES_COMMIT"
}
]
}