CVE-2023-6237

Issue summary: Checking excessively long invalid RSA public keys may take a long time. Impact summary: Applications that use the function EVP_PKEY_public_check() to check RSA public keys may experience long delays. Where the key that is being checked has been obtained from an untrusted source this may lead to a Denial of Service. When function EVP_PKEY_public_check() is called on RSA public keys, a computation is done to confirm that the RSA modulus, n, is composite. For valid RSA keys, n is a product of two or more large primes and this computation completes quickly. However, if n is an overly large prime, then this computation would take a long time. An application that calls EVP_PKEY_public_check() and supplies an RSA key obtained from an untrusted source could be vulnerable to a Denial of Service attack. The function EVP_PKEY_public_check() is not called from other OpenSSL functions however it is called from the OpenSSL pkey command line application. For that reason that application is also vulnerable if used with the '-pubin' and '-check' options on untrusted data. The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are affected by this issue.

Read the notes from the security team

Why is this CVE low priority?

Upstream OpenSSL project has rated this as low severity

Learn more about Ubuntu priority

Status

Show unmaintained releases

Package	Ubuntu Release	Status
edk2	24.10 oracular	Vulnerable
	24.04 LTS noble	Vulnerable
	23.10 mantic	Not affected
	23.04 lunar	Not affected
	22.04 LTS jammy	Not affected
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Ignored end of standard support
nodejs	24.10 oracular	Not affected
	24.04 LTS noble	Not affected
	23.10 mantic	Not affected
	23.04 lunar	Not affected
	22.04 LTS jammy	Vulnerable
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Needs evaluation
	14.04 LTS trusty	Not affected
openssl	24.10 oracular	Fixed 3.0.10-1ubuntu4
	24.04 LTS noble	Fixed 3.0.10-1ubuntu4
	23.10 mantic	Fixed 3.0.10-1ubuntu2.2
	23.04 lunar	Ignored end of life, was needed
	22.04 LTS jammy	Fixed 3.0.2-0ubuntu1.14
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected
openssl1.0	24.10 oracular	Not in release
	24.04 LTS noble	Not in release
	23.10 mantic	Not in release
	23.04 lunar	Not in release
	22.04 LTS jammy	Not in release
	20.04 LTS focal	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release

Notes

mdeslaur

only affects 3.0 and higher

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
openssl	Upstream: https://git.openssl.org/?p=openssl.git;a=commit;h=18c02492138d1eb8b6548cb26e7b625fb2414a2a

References

Related Ubuntu Security Notices (USN)