Ecdsa — CraftedSignal Threat Feedhttps://feed.craftedsignal.io/tags/ecdsa/Trending threats, MITRE ATT&CK coverage, and detection metadata — refreshed continuously.Hugoenhello@craftedsignal.iohello@craftedsignal.ioWed, 03 Jan 2024 12:00:00 +0000CVE-2019-1547 ECDSA Remote Timing Attack Vulnerabilityhttps://feed.craftedsignal.io/briefs/2024-01-03-cve-2019-1547/Wed, 03 Jan 2024 12:00:00 +0000hello@craftedsignal.iohttps://feed.craftedsignal.io/briefs/2024-01-03-cve-2019-1547/CVE-2019-1547 is a security vulnerability that could allow a remote timing attack.CVE-2019-1547 is a security vulnerability impacting Microsoft products. While specific details regarding the exploitation and impact are not fully available in the provided source, the vulnerability is described as related to an ECDSA remote timing attack. Timing attacks exploit the time it takes to execute cryptographic algorithms to potentially reveal sensitive information. Defenders should closely monitor for any updates or advisories from Microsoft regarding this CVE and take necessary patching steps when available. This vulnerability requires further investigation based on product-specific usage and exposure.

Attack Chain

Due to the limited information, the attack chain is based on a general understanding of timing attacks:

  1. An attacker identifies a target system running a vulnerable version of software leveraging ECDSA.
  2. The attacker sends specially crafted requests to the target system.
  3. The target system processes the request using the vulnerable ECDSA implementation.
  4. By measuring the time it takes for the target to respond to different requests, the attacker gathers timing data.
  5. The attacker analyzes the timing data to infer information about the private key used in the ECDSA implementation.
  6. With sufficient timing data, the attacker may be able to reconstruct portions of the private key.
  7. The attacker uses the reconstructed key material to impersonate the target or decrypt communications.

Impact

The successful exploitation of CVE-2019-1547 could allow an attacker to potentially recover private keys used in ECDSA implementations. This could lead to unauthorized access, impersonation, or decryption of sensitive data. Without specific details on affected products and deployment scenarios, the exact scope of impact is difficult to ascertain. The severity depends on which systems rely on the vulnerable ECDSA implementation and the sensitivity of the data protected by those systems.

Recommendation

  • Monitor Microsoft’s Security Update Guide for specific details and patches related to CVE-2019-1547 (https://msrc.microsoft.com/update-guide/vulnerability/CVE-2019-1547).
  • Implement network monitoring to detect unusual patterns in network traffic that may indicate timing attacks.
  • Consider deploying web server rules to flag requests with anomalous timing characteristics based on webserver logs.
]]>mediumadvisorycve-2019-1547timing-attackecdsaCVE-2018-0735 ECDSA Signature Generation Timing Attackhttps://feed.craftedsignal.io/briefs/2024-01-ecdsa-timing-attack/Tue, 02 Jan 2024 12:00:00 +0000hello@craftedsignal.iohttps://feed.craftedsignal.io/briefs/2024-01-ecdsa-timing-attack/CVE-2018-0735 is a timing attack vulnerability in ECDSA signature generation affecting Microsoft products, potentially allowing attackers to recover private keys.CVE-2018-0735 describes a timing attack vulnerability affecting the Elliptic Curve Digital Signature Algorithm (ECDSA) implementation within certain Microsoft products. Successful exploitation of this vulnerability could allow a remote attacker to recover the private key used to generate digital signatures. The vulnerability stems from the time it takes to generate signatures, which varies in ways predictable to an attacker. ECDSA is commonly used for authentication and encryption, making this a serious concern. While the specific affected products are not detailed without enabling JavaScript on the source webpage, the vulnerability has the potential to impact various applications and services that rely on Microsoft’s ECDSA implementation for cryptographic operations.

Attack Chain

Due to limited information from the source, a detailed attack chain is not available. However, a general ECDSA timing attack would involve the following steps:

  1. The attacker identifies a target system or application utilizing a vulnerable ECDSA implementation from Microsoft.
  2. The attacker initiates a series of signature requests, potentially through legitimate or malicious channels depending on the application.
  3. The attacker measures the time taken to generate each signature with high precision.
  4. The attacker performs statistical analysis on the timing data, looking for correlations between the timing and the secret nonce value used during signature generation.
  5. Through repeated signature requests and timing analysis, the attacker reconstructs the secret nonce value used in multiple signature generations.
  6. Once the attacker obtains sufficient nonce values and corresponding signatures, they can recover the private key used for signing.
  7. With the private key, the attacker can forge signatures, impersonate the legitimate entity, and potentially gain unauthorized access to sensitive data or systems.

Impact

Successful exploitation of CVE-2018-0735 could allow an attacker to recover the private key used for ECDSA signature generation. This could lead to a complete compromise of trust, as the attacker can forge signatures and impersonate the legitimate entity. The impact would vary depending on the specific application, but potential consequences include unauthorized access to systems, data breaches, and the ability to install malware or conduct man-in-the-middle attacks. The number of affected systems would depend on the widespread use of the vulnerable ECDSA implementation within Microsoft products.

Recommendation

  • Consult Microsoft’s Security Update Guide (https://msrc.microsoft.com/update-guide/vulnerability/CVE-2018-0735) for specific affected products and available patches to mitigate CVE-2018-0735.
  • Although a specific network IOC is unavailable, monitor network traffic for unusual patterns or high volumes of signature requests originating from single sources to potentially detect reconnaissance activity related to timing attacks.
  • Enable detailed logging of cryptographic operations to enable investigation in case of suspicion of private key compromise.
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