CVE-2018-1000888

Exp

PEAR Archive_Tar version 1.4.3 and earlier contains a CWE-502, CWE-915 vulnerability in the Archive_Tar class. There are several file operations with `$v_header['filename']` as parameter (such as file_exists, is_file, is_dir, etc). When extract is called without a specific prefix path, we can trigger unserialization by crafting a tar file with `phar://[path_to_malicious_phar_file]` as path. Object injection can be used to trigger destruct in the loaded PHP classes, e.g. the Archive_Tar class itself. With Archive_Tar object injection, arbitrary file deletion can occur because `@unlink($this->_temp_tarname)` is called. If another class with useful gadget is loaded, it may possible to cause remote code execution that can result in files being deleted or possibly modified. This vulnerability appears to have been fixed in 1.4.4.

Published: 2018-12-28 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-1000888 is rated High Exploit Risk (82.6/100): CVSS High severity, with high exploitation likelihood (EPSS 18.29%, 97th percentile). 4 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2018-1000888

EDB-ID Source Kind Published Link
46108 exploit_db edb 2019-01-10 Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2018-1000888

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 2026-06-15 19.75% 18.29% -1.46%
2 2026-06-14 24.69% 19.75% -4.94%
3 2026-05-29 — 24.69% —

Full EPSS history (26 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-1000888

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
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.
 2.8 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2018-1000888

GitHub Security Advisory for CVE-2018-1000888

GHSA-3q76-jq6m-573p · Severity: high · Ecosystem: composer — Archive_Tar contains Potential RCE if filename starts with phar://

OS Trackers for CVE-2018-1000888

vendor priority summary link
alpine high CVE-2018-1000888: 1 source package rows (drupal7); 5 state rows across 5 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, edge-community); fixed 5, open 0. https://security.alpinelinux.org/vuln/CVE-2018-1000888
debian not yet assigned CVE-2018-1000888 not yet assigned priority: Debian including 1 source packages (php-pear), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-1000888
gentoo normal CVE-2018-1000888: 1 GLSA(s) (202006-14), 1 atom(s) (dev-php/PEAR-Archive_Tar); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2018-1000888
redhat medium — https://access.redhat.com/security/cve/CVE-2018-1000888
ubuntu medium CVE-2018-1000888 medium priority: Ubuntu including 1 source packages (php-pear), 5 status rows across 5 suites (bionic, cosmic, trusty, upstream, xenial): released 4, DNE 1. https://ubuntu.com/security/CVE-2018-1000888

Affected software / configurations for CVE-2018-1000888

Vendor Product Version Raw CPE
php pear_archive_tar <= 1.4.3 cpe:2.3:a:php:pear_archive_tar:*:*:*:*:*:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.10 cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

References for CVE-2018-1000888

cvelogic Threat Intelligence