CVE-2023-49316 Phpseclib needs guardrails on large binaryfield integers
Attackers can cause denial of service in phpseclib by supplying excessively large degrees to the BinaryField class.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-49316?
CVE-2023-49316 is a high-severity denial of service vulnerability in n/a, published on 27 Nov 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In Math/BinaryField.php in phpseclib 3 before 3.0.34, excessively large degrees can lead to a denial of service.
Weakness: CWE-834
Which versions are affected by CVE-2023-49316?
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 | 3.0.34 |
phpseclib/phpseclib Packagist | From 3.0.0 | 3.0.34 |
Products include Phpseclib Phpseclib.
How do I fix CVE-2023-49316?
Upgrade phpseclib/phpseclib to 3.0.34 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-2023-49316 being exploited?
There is no known exploitation of CVE-2023-49316 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-2023-27560 phpseclib Infinite Loop vulnerability
- 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-2023-49316, GHSA-2f25-pfq3-c7h8, UBUNTU-CVE-2023-49316.