CVE-2023-27560 phpseclib Infinite Loop vulnerability
An attacker can cause a denial of service via an infinite loop in the PrimeField component of the phpseclib library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-27560?
CVE-2023-27560 is a high-severity denial of service vulnerability in n/a, published on 3 Mar 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Math/PrimeField.php in phpseclib 3.x before 3.0.19 has an infinite loop with composite primefields.
Weakness: CWE-835
Which versions are affected by CVE-2023-27560?
2 open source packages ship an affected version, including phpseclib/phpseclib. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
phpseclib/phpseclib Packagist | From 3.0.0 | 3.0.19 |
phpseclib/phpseclib Packagist | From 3.0.0 | 3.0.19 |
Products include Phpseclib Phpseclib.
How do I fix CVE-2023-27560?
Upgrade phpseclib/phpseclib to 3.0.19 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-27560 being exploited?
There is no known exploitation of CVE-2023-27560 in the wild and no public exploit code.
Other vulnerabilities in n/a
- CVE-2026-32935 phpseclib's AES-CBC unpadding susceptible to padding oracle timing attack
- CVE-2023-52892 Name confusion in x509 Subject Alternative Name fields
- CVE-2023-49316 Phpseclib needs guardrails on large binaryfield integers
- CVE-2026-55599 phpseclib: X.509 certificate validation sends attacker-controlled outbound requests (server-side request forgery) via Authority Information Access
- CVE-2026-40194 phpseclib has a variable-time HMAC comparison in SSH2::get_binary_packet() using != instead of hash_equals()
Sources
Also known as DEBIAN-CVE-2023-27560, GHSA-hm7p-r324-hhf3, UBUNTU-CVE-2023-27560.