Description

Improper input validation in Sync in Google Chrome prior to 152.0.7977.65 allowed a remote attacker to obtain sensitive information via crafted network traffic. (Chromium security severity: Medium)

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.5",
  "pubDate": "2026-08-25T21:18:03.390Z",
  "pubdate": "2026-08-25T21:18:03.390Z",
  "executiveSummary": "A vulnerability categorized as improper input validation exists within the Sync component of Google Chrome.\nThis flaw allows a remote, unauthenticated attacker to induce the disclosure of sensitive information.\nThe vulnerability affects versions of Google Chrome prior to 152.0.7977.65.\nThe primary risk involves the unauthorized exposure of data synchronized through the browser's internal systems.\nExploitation requires the attacker to transmit crafted network traffic to a vulnerable client, bypassing standard input validation checks.\nThe Chromium project has classified the security severity of this issue as Medium, reflecting the impact on user privacy and data confidentiality.\nAttackers can leverage this vulnerability to gain unauthorized access to information that would otherwise be protected by internal browser security protocols.",
  "technicalDetails": "The vulnerability resides within the Sync component of the Chromium codebase, which handles the synchronization of user data, such as bookmarks, history, and preferences, between browser instances.\nThe root cause is identified as improper input validation occurring during the parsing or handling of network-based synchronization data structures.\nWhen the Sync component receives incoming data from a remote source, it fails to sufficiently sanitize or validate the format and content of the received payloads.\nA remote attacker can exploit this by crafting malicious network traffic designed to trigger unexpected behavior in the Sync component's state machine or data serialization logic.\nThe attack flow initiates when the attacker sends a specifically crafted sequence of packets that interact with the Sync protocol. Because the input validation logic is deficient, the browser processes these packets as legitimate sync instructions.\nThis processing error can lead to a memory corruption event or an logic-based state inconsistency, causing the browser to disclose sensitive information present in the Sync buffer or internal memory structures back to the attacker over the network.\nThe vulnerability does not require authentication from the victim, as the Sync component is designed to listen for and process incoming network traffic to facilitate service functionality.\nBecause the defect exists in the input handling layer of the Sync process, the browser effectively acts as an oracle, revealing private information upon receiving a malformed request.\nThis exploitation technique allows for the retrieval of potentially sensitive configuration data or synchronized state information without the user's consent or interaction.\nThe impact of a successful exploit includes the compromise of user-specific data that is stored and processed by the synchronization infrastructure. Post-exploitation, an attacker may use this revealed data to gain further insights into user activities or to facilitate downstream attacks by leveraging the information disclosed during the initial handshake or data exchange phase of the Sync protocol."
}