CVE-2008-5620 in RoundCube
Summary
by MITRE
RoundCube Webmail (roundcubemail) before 0.2-beta allows remote attackers to cause a denial of service (memory consumption) via crafted size parameters that are used to create a large quota image.
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Analysis
by VulDB Data Team • 05/24/2025
RoundCube Webmail version 0.2-beta contains a critical vulnerability that enables remote attackers to consume excessive system memory and potentially cause denial of service conditions through specifically crafted size parameters. This vulnerability resides in the quota image generation functionality where the application fails to properly validate or limit user-supplied dimension parameters. When attackers submit malicious size values, the system attempts to create oversized quota images that consume disproportionate amounts of memory resources. The flaw demonstrates characteristics consistent with CWE-134, which addresses the use of externally-influenced format strings, though in this case the vulnerability manifests through improper parameter handling rather than format string manipulation. The vulnerability operates at the application layer and can be exploited through web-based interfaces without requiring authentication or special privileges. Attackers can leverage this weakness to exhaust available memory on the server, leading to service disruption and potential system instability. The impact extends beyond simple denial of service as excessive memory consumption can affect other applications running on the same system, creating cascading effects that compromise overall system availability. This vulnerability aligns with ATT&CK technique T1499.004, which covers network denial of service attacks through resource exhaustion. The flaw represents a classic case of insufficient input validation where user-provided parameters directly influence memory allocation decisions within the application. The vulnerability is particularly concerning because it can be triggered through simple web requests, making it accessible to attackers with basic web browsing capabilities. The lack of parameter bounds checking in the quota image generation module creates an exploitable path where attackers can specify arbitrarily large dimensions, causing the system to allocate memory proportional to the requested size. This memory exhaustion attack can be particularly devastating in environments where RoundCube is deployed with limited memory resources or where multiple users can submit requests simultaneously. The vulnerability also demonstrates poor defensive programming practices, as the system fails to implement proper resource limits or sanity checks on user inputs. Organizations running affected versions of RoundCube should consider immediate remediation through patch updates to version 0.2-beta or later releases that address this memory consumption issue. Additional mitigations may include implementing rate limiting, input validation at the web server level, and monitoring for unusual memory consumption patterns that could indicate exploitation attempts. The vulnerability serves as a reminder of the importance of validating all user inputs and implementing proper resource management controls to prevent attackers from manipulating application behavior through memory allocation attacks.