A recent vulnerability, identified as CVE-2025-22376, has been discovered in the Net::OAuth package (used for implementing OAuth authorization protocol) for Perl programming language. This security issue exists in the Net::OAuth::Client module, which is a part of the package, and specifically affects versions before .29. The vulnerability lies in the default nonce (number used once) generation, which is created using a weak 32-bit integer, potentially making it susceptible to attacks.
Vulnerability Details
In the OAuth protocol, a nonce is used to ensure that the same request is not submitted multiple times, preventing replay attacks. However, the Net::OAuth::Client in the Net::OAuth package (before .29) uses a weak default nonce generated from Perl's built-in rand() function. This default nonce is a 32-bit integer, which is not cryptographically strong and can be easily guessed by attackers.
This weak nonce generation can lead to security risks, as attackers may be able to guess the nonce and subsequently manipulate the OAuth request tokens, leading to unauthorized access to the protected resources.
The vulnerable code snippet in Net::OAuth::Client (before .29) can be found below
sub _nonce {
my $self = shift;
return int(rand(2**32));
}
As seen in the above code, the _nonce() function generates the default nonce by using the built-in rand() function, returning a 32-bit integer. This default nonce generation method lacks sufficient cryptographic strength, making it easier for attackers to guess.
Exploit and Mitigation
Currently, there are no known exploits for this vulnerability. However, as a precaution, it is recommended to update the Net::OAuth package to version .29 or later. By doing so, the weak default nonce generation issue will be resolved.
For developers who cannot upgrade immediately or prefer manual workarounds, one possible mitigation is to implement a custom nonce generation function that uses a stronger cryptographic method, such as Perl's Crypt::PRNG module:
use Crypt::PRNG qw(random_string);
sub _nonce {
my $self = shift;
return random_string(16); # 16-byte random string
}
This custom nonce function leverages the Crypt::PRNG module to generate a cryptographically-strong random string, significantly improving security.
Original References
1. Net::OAuth Package: https://metacpan.org/pod/Net::OAuth
2. Net::OAuth::Client: https://metacpan.org/pod/Net::OAuth::Client
3. CVE Details: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-22376
4. Net::OAuth Changelog: https://metacpan.org/source/KEETHI/Net-OAuth-.29/Changes
5. Crypt::PRNG: https://metacpan.org/pod/Crypt::PRNG
Conclusion
In conclusion, the CVE-2025-22376 vulnerability in the Net::OAuth package for Perl highlights the importance of using strong cryptographic methods in nonce generation. By updating the package to version .29 or implementing a custom, secure nonce function, developers can secure their Perl applications against potential attacks and ensure the integrity of their OAuth implementations.
Timeline
Published on: 01/03/2025 22:15:07 UTC
Last modified on: 01/03/2025 23:15:08 UTC