// For flags

CVE-2025-43857

net-imap rubygem vulnerable to possible DoS by memory exhaustion

Severity Score

6.0
*CVSS v4

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.5.7, 0.4.20, 0.3.9, and 0.2.5, there is a possibility for denial of service by memory exhaustion when net-imap reads server responses. At any time while the client is connected, a malicious server can send can send a "literal" byte count, which is automatically read by the client's receiver thread. The response reader immediately allocates memory for the number of bytes indicated by the server response. This should not be an issue when securely connecting to trusted IMAP servers that are well-behaved. It can affect insecure connections and buggy, untrusted, or compromised servers (for example, connecting to a user supplied hostname). This issue has been patched in versions 0.5.7, 0.4.20, 0.3.9, and 0.2.5.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
None
User Interaction
Passive
System
Vulnerable | Subsequent
Confidentiality
None
None
Integrity
None
None
Availability
High
None
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
None
Integrity
None
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2025-04-17 CVE Reserved
  • 2025-04-28 CVE Published
  • 2025-04-28 CVE Updated
  • 2025-07-05 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-400: Uncontrolled Resource Consumption
  • CWE-405: Asymmetric Resource Consumption (Amplification)
  • CWE-770: Allocation of Resources Without Limits or Throttling
  • CWE-789: Memory Allocation with Excessive Size Value
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Ruby
Search vendor "Ruby"
 Net-imap
Search vendor "Ruby" for product "Net-imap"
 >= 0.5.0 < 0.5.7
Search vendor "Ruby" for product "Net-imap" and version " >= 0.5.0 < 0.5.7"
en
Affected
Ruby
Search vendor "Ruby"
 Net-imap
Search vendor "Ruby" for product "Net-imap"
 >= 0.4.0 < 0.4.20
Search vendor "Ruby" for product "Net-imap" and version " >= 0.4.0 < 0.4.20"
en
Affected
Ruby
Search vendor "Ruby"
 Net-imap
Search vendor "Ruby" for product "Net-imap"
 >= 0.3.0 < 0.3.9
Search vendor "Ruby" for product "Net-imap" and version " >= 0.3.0 < 0.3.9"
en
Affected
Ruby
Search vendor "Ruby"
 Net-imap
Search vendor "Ruby" for product "Net-imap"
 < 0.2.5
Search vendor "Ruby" for product "Net-imap" and version " < 0.2.5"
en
Affected