OpenSSL Project released 1.1.1k version to fix two High
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2021-3450 +1 in the same advisory: …3449 | The X509_V_FLAG_X509_STRICT flag enables additional security checks of the certificates present in a certificate chain. The X509_V_FLAG_X509_STRICT flag enables additional security checks of the certificates present in a certificate chain. It is not set by default. Starting from OpenSSL version 1.1.1h a check to disallow certificates in the chain that have explicitly encoded elliptic curve parameters was added as an additional strict check. An error in the implementation of this check meant that the result of a previous check to confirm that certificates in the chain are valid CA certificates was overwritten. This effectively bypasses the check that non-CA certificates must not be able to issue other certificates. If a "purpose" has been configured then there is a subsequent opportunity for checks that the certificate is a valid CA. All of the named "purpose" values implemented in libcrypto perform this check. Therefore, where a purpose is set the certificate chain will still be rejected even when the strict flag has been used. A purpose is set by default in libssl client and server certificate verification routines, but it can be overridden or removed by an application. In order to be affected, an application must explicitly set the X509_V_FLAG_X509_STRICT verification flag and either not set a purpose for the certificate verification or, in the case of TLS client or server applications, override the default purpose. OpenSSL versions 1.1.1h and newer are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1k. OpenSSL 1.0.2 is not impacted by this issue. Fixed in OpenSSL 1.1.1k (Affected 1.1.1h-1.1.1j). NVD description · AI analysis pending | 7.4 group max | 18% |
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Full article347 words · extracted from securityaffairs.com · click to collapse
The OpenSSL Project addresses two high-severity vulnerabilities, including one related to verifying a certificate chain and one that can trigger a DoS condition.
The OpenSSL Project this week released version 1.1.1k to address two high-severity vulnerabilities, respectively tracked as CVE-2021-3450 and CVE-2021-3449.
The CVE-2021-3449 vulnerability could be exploited to trigger a DoS condition by sending a specially crafted renegotiation ClientHello message from a client.
“An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. If a TLSv1.2 renegotiation ClientHello omits the signature_algorithms extension (where it was present in the initial ClientHello), but includes a signature_algorithms_cert extension then a NULL pointer dereference will result, leading to a crash and a denial of service attack,” State the advisory.
The issue affects servers running OpenSSL 1.1.1 versions with TLS 1.2 and renegotiation enabled, which is the default configuration. The vulnerability was reported by Peter Kästle and Samuel Sapalski from Nokia.
The CVE-2021-3450 vulnerability is related to the verification of a certificate chain when using the X509_V_FLAG_X509_STRICT flag.
“The X509_V_FLAG_X509_STRICT flag enables additional security checks of the certificates present in a certificate chain. It is not set by default. Starting from OpenSSL version 1.1.1h a check to disallow certificates in the chain that have explicitly encoded elliptic curve parameters was added as an additional strict check.” reads the advisory published by the OpenSSL Project. “An error in the implementation of this check meant that the result of a previous check to confirm that certificates in the chain are valid CA certificates was overwritten. This effectively bypasses the check that non-CA certificates must not be able to issue other certificates,”
The vulnerability was reported by Benjamin Kaduk and Xiang Ding from Akamai.
In February 2021, the OpenSSL Project released security patches to address three vulnerabilities, two denial-of-service (DoS) flaws, and an incorrect SSLv2 rollback protection issue.
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Text extracted automatically; images, tables and formatting may be missing. Original: https://securityaffairs.com/115968/security/openssl-flaws-2.html