Buffer Overflow in SSL related code (CVE-2017-8818)
Summary
Vulnerability in SSL related code (CVE-2017-8818). Successful exploitation can lead to full system takeover. Exploitable via connectdata.
Original description
The description as published by the source.
libcurl contains an out boundary access flaw in SSL related code.
When allocating memory for a connection (the internal struct called
connectdata), a certain amount of memory is allocated at the end of the
struct to be used for SSL related structs. Those structs are used by the
particular SSL library libcurl is built to use. The application can also tell
libcurl which specific SSL library to use if it was built to support more than
one.
The math used to calculate the extra memory amount necessary for the SSL
library was wrong on 32-bit systems, which made the allocated memory too small
by 4 bytes. The last struct member of the last object within the memory area
could then be outside of what was allocated. Accessing that member could lead
to a crash or other undefined behaviors depending on what memory that is
present there and how the particular SSL library decides to act on that memory
content.
Specifically the vulnerability is present if libcurl was built so that
sizeof(long long *) < sizeof(long long) which as far as we are aware only
happens in 32-bit builds.
Source: NIST National Vulnerability Database NVD
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-2017-8818 has been found in SSL related code.
Attackers can target a specific entry point like connectdata over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 9.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "SSL related code CVE-2017-8818" on the vendor's site.
CVE-2017-8818 (SSL related code) — CWE-119 / CVSS v3 9.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: connectdata
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.
A vulnerability (CWE-119) exists in SSL related code. Attackers reach the vulnerable code path via connectdata without authentication.
Check the vendor advisory for the affected versions of SSL related code. Attack surface: connectdata.
Severity: Critical (CVSS 9.8/10). Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
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
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで SSL related code を使っているサービスとバージョンを洗い出す。
-
2Post-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-2017-8818 curl Fixed in: 7.57.0-r0
- Debian DEBIAN-CVE-2017-8818 curl Fixed in: 7.57.0-1
References
- advisory security.cucumberlinux.com
- advisory securityfocus.com
- advisory securitytracker.com
- advisory security.gentoo.org
- patch curl.haxx.se