CVE-2021-23839 (Low) detected in OpenSSLOpenSSL_1_1_1g

[mend-bolt-for-github[bot]]

CVE-2021-23839 - Low Severity Vulnerability

Vulnerable Library - OpenSSLOpenSSL_1_1_1g

TLS/SSL and crypto library

Library home page: https://github.com/OpenSSL/OpenSSL.git

Found in HEAD commit: d39c694989345b5957f69a26018e620470e49916

Found in base branch: master

Vulnerable Source Files (1)

/crypto/rsa/rsa_ssl.c

Vulnerability Details

OpenSSL 1.0.2 supports SSLv2. If a client attempts to negotiate SSLv2 with a server that is configured to support both SSLv2 and more recent SSL and TLS versions then a check is made for a version rollback attack when unpadding an RSA signature. Clients that support SSL or TLS versions greater than SSLv2 are supposed to use a special form of padding. A server that supports greater than SSLv2 is supposed to reject connection attempts from a client where this special form of padding is present, because this indicates that a version rollback has occurred (i.e. both client and server support greater than SSLv2, and yet this is the version that is being requested). The implementation of this padding check inverted the logic so that the connection attempt is accepted if the padding is present, and rejected if it is absent. This means that such as server will accept a connection if a version rollback attack has occurred. Further the server will erroneously reject a connection if a normal SSLv2 connection attempt is made. Only OpenSSL 1.0.2 servers from version 1.0.2s to 1.0.2x are affected by this issue. In order to be vulnerable a 1.0.2 server must: 1) have configured SSLv2 support at compile time (this is off by default), 2) have configured SSLv2 support at runtime (this is off by default), 3) have configured SSLv2 ciphersuites (these are not in the default ciphersuite list) OpenSSL 1.1.1 does not have SSLv2 support and therefore is not vulnerable to this issue. The underlying error is in the implementation of the RSA_padding_check_SSLv23() function. This also affects the RSA_SSLV23_PADDING padding mode used by various other functions. Although 1.1.1 does not support SSLv2 the RSA_padding_check_SSLv23() function still exists, as does the RSA_SSLV23_PADDING padding mode. Applications that directly call that function or use that padding mode will encounter this issue. However since there is no support for the SSLv2 protocol in 1.1.1 this is considered a bug and not a security issue in that version. OpenSSL 1.0.2 is out of support and no longer receiving public updates. Premium support customers of OpenSSL 1.0.2 should upgrade to 1.0.2y. Other users should upgrade to 1.1.1j. Fixed in OpenSSL 1.0.2y (Affected 1.0.2s-1.0.2x).

Publish Date: 2021-02-16

URL: CVE-2021-23839

CVSS 3 Score Details (3.7)

Base Score Metrics: - Exploitability Metrics: - Attack Vector: Network - Attack Complexity: High - Privileges Required: None - User Interaction: None - Scope: Unchanged - Impact Metrics: - Confidentiality Impact: None - Integrity Impact: Low - Availability Impact: None

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Origin: https://security.netapp.com/advisory/ntap-20210219-0009/

Release Date: 2021-02-16

Fix Resolution: OpenSSL_1_1_1j

---

Step up your Open Source Security Game with Mend here

[mend-bolt-for-github[bot]]

:heavy_check_mark: This issue was automatically closed by Mend because the vulnerable library in the specific branch(es) was either marked as ignored or it is no longer part of the Mend inventory.

[mend-bolt-for-github[bot]]

:information_source: This issue was automatically re-opened by Mend because the vulnerable library in the specific branch(es) has been detected in the Mend inventory.