In libssh2 before 1.9.0, kex_method_diffie_hellman_group_exc… (CVE-2019-13115)

Summary

Vulnerability reported (CVE-2019-13115). Confidential information can be exposed externally. Mitigation: upgrade to 1.8.1 or later.

Original description

The description as published by the source.

In libssh2 before 1.9.0, kex_method_diffie_hellman_group_exchange_sha256_key_exchange in kex.c has an integer overflow that could lead to an out-of-bounds read in the way packets are read from the server. A remote attacker who compromises a SSH server may be able to disclose sensitive information or cause a denial of service condition on the client system when a user connects to the server. This is related to an _libssh2_check_length mistake, and is different from the various issues fixed in 1.8.1, such as CVE-2019-3855.

Source: OSV.dev (Open Source Vulnerabilities) NVD OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2019-13115 has been found.
Confidential information can be exposed externally.
What to do: upgrade the affected software to 1.8.1 or later.
If unsure, ask your IT team or search "CVE-2019-13115" on the vendor's site.

CVE-2019-13115
Attack vector: remote (network-reachable) / unauthenticated
Patched: 1.8.1 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) has been reported.

📍 Affected scope

Check the vendor advisory for the affected versions.

🔥 Severity

Severity: ?. Confidential information can be exposed externally.

🔧 How to fix

Update to 1.8.1.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
Audit SBOM/dependencies for affected components.
```
資産台帳・SBOM・依存マニフェストで影響コンポーネントを特定する。
2
Apply patch patch
```
Upgrade to 1.8.1
```
ステージング環境で 1.8.1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Fix status by distribution

Fixed packages published by each distribution for this CVE

Alpine Linux ALPINE-CVE-2019-13115 libssh2 Fixed in: 1.9.0-r0

In libssh2 before 1.9.0, kex_method_diffie_hellman_group_exchange_sha256_key_exchange in kex.c has an integer overflow…