EUVD-2025-20227
CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
4Description
A flaw was found in libssh when using the ChaCha20 cipher with the OpenSSL library. If an attacker manages to exhaust the heap space, this error is not detected and may lead to libssh using a partially initialized cipher context. This occurs because the OpenSSL error code returned aliases with the SSH_OK code, resulting in libssh not properly detecting the error returned by the OpenSSL library. This issue can lead to undefined behavior, including compromised data confidentiality and integrity or crashes.
Analysis
A flaw was found in libssh when using the ChaCha20 cipher with the OpenSSL library.
Technical Context
A denial of service vulnerability allows an attacker to disrupt the normal functioning of a system, making it unavailable to legitimate users. This vulnerability is classified as Return of Wrong Status Code (CWE-393).
Affected Products
Affected products: Libssh Libssh
Remediation
Implement rate limiting and input validation. Use timeout mechanisms for resource-intensive operations. Deploy DDoS protection where applicable.
Priority Score
Vendor Status
Ubuntu
Priority: Medium| Release | Status | Version |
|---|---|---|
| noble | released | 0.10.6-2ubuntu0.1 |
| oracular | released | 0.10.6-3ubuntu1.1 |
| plucky | released | 0.11.1-1ubuntu0.1 |
| upstream | released | 0.11.2 |
| bionic | not-affected | code not present |
| focal | not-affected | code not present |
| jammy | not-affected | code not present |
| xenial | not-affected | code not present |
Debian
Bug #1108407| Release | Status | Fixed Version | Urgency |
|---|---|---|---|
| bullseye | not-affected | - | - |
| bullseye (security) | fixed | 0.9.8-0+deb11u2 | - |
| bookworm | fixed | 0.10.6-0+deb12u2 | - |
| bookworm (security) | vulnerable | 0.10.6-0+deb12u1 | - |
| trixie | fixed | 0.11.2-1+deb13u1 | - |
| forky | fixed | 0.11.3-1 | - |
| sid | fixed | 0.12.0-1 | - |
| (unstable) | fixed | 0.11.2-1 | - |
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External POC / Exploit Code
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