OpenSSL up to 1.0.2t/1.1.1d Montgomery Square information disclosure

Summaryinfo

A vulnerability classified as critical has been found in OpenSSL up to 1.0.2t/1.1.1d. Affected is an unknown function of the component Montgomery Square Handler. This manipulation causes information disclosure. This vulnerability is handled as CVE-2019-1551. The attack can be initiated remotely. There is not any exploit available. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability was found in OpenSSL up to 1.0.2t/1.1.1d (Network Encryption Software). It has been declared as critical. Affected by this vulnerability is some unknown processing of the component Montgomery Square Handler. The manipulation with an unknown input leads to a information disclosure vulnerability. The CWE definition for the vulnerability is CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

There is an overflow bug in the x64_64 Montgomery squaring procedure used in exponentiation with 512-bit moduli. No EC algorithms are affected. Analysis suggests that attacks against 2-prime RSA1024, 3-prime RSA1536, and DSA1024 as a result of this defect would be very difficult to perform and are not believed likely. Attacks against DH512 are considered just feasible. However, for an attack the target would have to re-use the DH512 private key, which is not recommended anyway. Also applications directly using the low level API BN_mod_exp may be affected if they use BN_FLG_CONSTTIME. Fixed in OpenSSL 1.1.1e-dev (Affected 1.1.1-1.1.1d). Fixed in OpenSSL 1.0.2u-dev (Affected 1.0.2-1.0.2t).

The weakness was released 12/06/2019 as confirmed git commit (GIT Repository). The advisory is shared at git.openssl.org. This vulnerability is known as CVE-2019-1551 since 11/28/2018. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1592 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 211827 (Oracle Linux 9 : edk2 (ELSA-2024-12842)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.0.2u-dev or 1.1.1e-dev eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.openssl.org. The best possible mitigation is suggested to be patching the affected component.

The vulnerability is also documented in the vulnerability database at Tenable (211827). Entries connected to this vulnerability are available at VDB-158227, VDB-158374 and VDB-158407. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Network Encryption Software

Name

• OpenSSL

Version

• 1.0.2
• 1.0.2a
• 1.0.2b
• 1.0.2c
• 1.0.2d
• 1.0.2e
• 1.0.2f
• 1.0.2g
• 1.0.2h
• 1.0.2i
• 1.0.2j
• 1.0.2k
• 1.0.2l
• 1.0.2m
• 1.0.2n
• 1.0.2o
• 1.0.2p
• 1.0.2q
• 1.0.2r
• 1.0.2s
• 1.0.2t
• 1.1.1
• 1.1.1a
• 1.1.1b
• 1.1.1c
• 1.1.1d

License

• open-source

Website

• Product: https://www.openssl.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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