CVE-2019-25585 in Deluge
Summary
by MITRE • 03/22/2026
Deluge 1.3.15 contains a denial of service vulnerability that allows local attackers to crash the application by supplying an excessively long string in the Webseeds field. Attackers can paste a buffer of 5000 bytes into the Webseeds field during torrent creation to trigger an application crash.
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Analysis
by VulDB Data Team • 03/27/2026
The vulnerability identified as CVE-2019-25585 affects Deluge version 1.3.15 and represents a classic buffer overflow condition that manifests as a denial of service attack. This issue resides within the torrent creation process where the application fails to properly validate input length in the Webseeds field, creating an exploitable condition that can be leveraged by local attackers to disrupt service availability. The vulnerability specifically targets the application's handling of user-supplied data during torrent configuration, where the Webseeds field accepts peer information for distributed file sharing operations. When an attacker supplies an input string exceeding the application's expected buffer size, the program crashes due to memory corruption occurring during the processing of this malformed data.
The technical flaw in CVE-2019-25585 demonstrates characteristics consistent with CWE-121, which describes heap-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The vulnerability operates at the application layer where input validation fails to enforce reasonable length constraints on user-provided strings, particularly within the torrent creation workflow. The specific trigger involves pasting a 5000-byte buffer into the Webseeds field, which exceeds the internal buffer capacity and causes the application to terminate unexpectedly. This type of vulnerability falls under the category of input validation flaws that are commonly exploited in denial of service scenarios, representing a fundamental security weakness in the application's data handling mechanisms.
From an operational impact perspective, this vulnerability enables local attackers to achieve service disruption without requiring elevated privileges or complex attack vectors. The crash occurs during the torrent creation process, which means that any user with access to the Deluge application can potentially trigger the denial of service condition. The impact extends beyond simple service interruption as it can affect the entire torrent management functionality, potentially causing data loss or requiring manual intervention to restore normal operations. The vulnerability's local nature means that it does not require network exposure or external attack surfaces, making it particularly concerning for systems where multiple users have access to the application. This type of attack directly violates the principle of least privilege and can be used to disrupt legitimate user activities or create conditions for more sophisticated attacks.
Mitigation strategies for CVE-2019-25585 should focus on implementing proper input validation and buffer management techniques within the Deluge application. The most effective approach involves establishing strict length limits for the Webseeds field input, ensuring that all user-supplied data is properly sanitized before processing. Security controls should include implementing bounds checking mechanisms that prevent buffer overflows and establishing proper error handling routines that gracefully manage malformed inputs. Organizations should also consider applying the vendor-provided patch or upgrade to a newer version of Deluge that addresses this vulnerability. The mitigation approach aligns with ATT&CK technique T1499.004 which covers network denial of service attacks and emphasizes the importance of proper input validation to prevent exploitation of buffer overflow conditions. Additionally, implementing application whitelisting and access controls can help limit the attack surface by restricting which users can create torrents, thereby reducing the potential impact of this vulnerability.