How severe is CVE-2021-3850?

CVE-2021-3850 has a CVSS score of 9.1/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-3850?

CVE-2021-3850 affects the following packages: adodb/adodb-php (Packagist), adodb/adodb-php (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2021-3850?

Update adodb/adodb-php to 5.20.21 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-3850 is resolved across your whole dependency graph.

How do I detect CVE-2021-3850 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for adodb/adodb-php, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-3850 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2021-3850 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2021-3850, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2021-3850?

CVE-2021-3850 has an EPSS (Exploit Prediction Scoring System) score of 2.2%, placing it in the 82th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-3850?

CVE-2021-3850 is classified as CWE-305 (CWE-305), Improper Authentication (CWE-287). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-3850 published, and has it been updated?

CVE-2021-3850 was published on January 25, 2022 and was last updated on October 20, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘

🐘 Packagist

Not in CISA KEV

CRITICAL severity

CVE-2021-3850 — adodb-php

CRITICALFix: adodb/adodb@952de6c

CVE-2021-3850 is a critical-severity (CVSS 9.1) CWE-305 vulnerability in adodb/adodb-php. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for adodb/adodb-php — see the affected versions and patch details below.

Authentication Bypass in ADOdb/ADOdb

Also known asGHSA-65mj-7c86-79jf

Published

Jan 25, 2022

Updated

Oct 20, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

1 known

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

2.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs82th percentile — riskier than 82% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected

🐘adodb/adodb-php🐘adodb/adodb-php

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

Impact

An attacker can inject values into a PostgreSQL connection string by providing a parameter surrounded by single quotes.

Depending on how the library is used in the client software, this may allow an attacker to bypass the login process, gain access to the server's IP address, etc.

Patches

The vulnerability is fixed in ADOdb versions 5.20.21 (952de6c4273d9b1e91c2b838044f8c2111150c29) and 5.21.4 or later (b4d5ce70034c5aac3a1d51d317d93c037a0938d2).

The simplest patch is to delete line 29 in drivers/adodb-postgres64.inc.php:

diff --git a/drivers/adodb-postgres64.inc.php b/drivers/adodb-postgres64.inc.php
index d04b7f67..729d7141 100644
--- a/drivers/adodb-postgres64.inc.php
+++ b/drivers/adodb-postgres64.inc.php
@@ -26,7 +26,6 @@ function adodb_addslashes($s)
 {
    $len = strlen($s);
    if ($len == 0) return "''";
-   if (strncmp($s,"'",1) === 0 && substr($s,$len-1) == "'") return $s; // already quoted
 
    return "'".addslashes($s)."'";
 }

Workarounds

Ensure the parameters passed to ADOConnection::connect() or related functions (nConnect(), pConnect()) are not surrounded by single quotes.

Credits

Thanks to Emmet Leahy (@meme-lord) of Sorcery Ltd for reporting this vulnerability, and to the huntr team for their support.

References

Original issue report https://huntr.dev/bounties/bdf5f216-4499-4225-a737-b28bc6f5801c/
ADOdb reference issue #793

For more information

If you have any questions or comments about this advisory:

Add a note in issue #793
Contact the maintainers on Gitter

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`adodb/adodb-php`	all versions	5.20.21`composer require adodb/adodb-php:^5.20.21`
🐘Packagist	`adodb/adodb-php`	≥ 5.21.0&&< 5.21.4	5.21.4`composer require adodb/adodb-php:^5.21.4`

Affected Products

2 products · 2 configurations

Application

adodbadodb_project

≤ 5.20.21

range

debian linuxdebian

1 version

9.0

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Authentication Bypass by Primary Weakness in GitHub repository adodb/ado…

huntr.devNVDJan 2022

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for adodb/adodb-php, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update adodb/adodb-php to 5.20.21 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-3850 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

### Impact An attacker can inject values into a PostgreSQL connection string by providing a parameter surrounded by single quotes. Depending on how the library is used in the client software, this may allow an attacker to bypass the login process, gain access to the server's IP address, etc. ### Patches The vulnerability is fixed in ADOdb versions 5.20.21 (952de6c4273d9b1e91c2b838044f8c2111150c29) and 5.21.4 or later (b4d5ce70034c5aac3a1d51d317d93c037a0938d2). The simplest patch is to delete line 29 in `drivers/adodb-postgres64.inc.php`: ```php diff --git a/drivers/adodb-postgres64.inc.p