CVE-2023-47118 | Heap buffer overflow in T64 codec decompression

ClickHouse® is an open-source column-oriented database management system that allows generating analytical data reports in real-time. A heap buffer overflow issue was discovered in ClickHouse server. An attacker could send a specially crafted payload to the native interface exposed by default on port 9000/tcp, triggering a bug in the decompression logic of T64 codec that crashes the ClickHouse server process. This attack does not require authentication. Note that this exploit can also be triggered via HTTP protocol, however, the attacker will need a valid credential as the HTTP authentication take places first. This issue has been fixed in version 23.10.2.13-stable, 23.9.4.11-stable, 23.8.6.16-lts and 23.3.16.7-lts.

Published: 2023-12-20 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-47118 is rated Moderate Risk (48.7/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.39%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-47118

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-05-10 0.29% 0.39% +0.10%
2 2025-04-15 0.36% 0.29% -0.07%
3 2025-04-14 — 0.36% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-47118

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.0 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 4.7 [email protected]
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]

Weakness enumeration for CVE-2023-47118

OS Trackers for CVE-2023-47118

vendor priority summary link
debian unimportant CVE-2023-47118 unimportant priority: Debian including 1 source packages (clickhouse), 2 status rows across 2 suites (bookworm, bullseye): resolved 2. https://security-tracker.debian.org/tracker/CVE-2023-47118
ubuntu medium CVE-2023-47118 medium priority: Ubuntu including 1 source packages (clickhouse), 12 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 5, DNE 4, needs-triage 3. https://ubuntu.com/security/CVE-2023-47118

Affected software / configurations for CVE-2023-47118

Vendor Product Version Raw CPE
clickhouse clickhouse >= 23.3, < 23.3.16.7 cpe:2.3:a:clickhouse:clickhouse:*:*:*:*:lts:*:*:*
clickhouse clickhouse >= 23.8, < 23.8.6.16 cpe:2.3:a:clickhouse:clickhouse:*:*:*:*:lts:*:*:*
clickhouse clickhouse >= 23.9, < 23.9.4.11 cpe:2.3:a:clickhouse:clickhouse:*:*:*:*:*:*:*:*
clickhouse clickhouse >= 23.10, < 23.10.2.13 cpe:2.3:a:clickhouse:clickhouse:*:*:*:*:*:*:*:*
clickhouse clickhouse_cloud < 23.9.2.47475 cpe:2.3:a:clickhouse:clickhouse_cloud:*:*:*:*:*:*:*:*

References for CVE-2023-47118

cvelogic Threat Intelligence