GHSA-jjx5-fq5g-8xpc CVE-2016-1902
Symfony Cryptographic Vulnerability
- Severity
- 7.5 / 10
- High · CVSS 3.0
- Exploit chance (EPSS)
- 1.91%
- Chance of exploitation in the next 30 days. Higher than 79.75% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-332 Insufficient Entropy in PRNG
- Fix
- Available
- 3 packages have a fixed version
Description
The nextBytes function in the SecureRandom class in Symfony before 2.3.37, 2.6.x before 2.6.13, and 2.7.x before 2.7.9 does not properly generate random numbers when used with PHP 5.x without the paragonie/random_compat library and the openssl_random_pseudo_bytes function fails, which makes it easier for attackers to defeat cryptographic protection mechanisms via unspecified vectors.
Affected versions
Packagist
| Package | Vulnerable | Fixed in |
|---|---|---|
| symfony/security | >= 2.3.0, < 2.3.37 |
2.3.37 |
| symfony/security | >= 2.4.0, < 2.6.13 |
2.6.13 |
| symfony/security | >= 2.7.0, < 2.7.9 |
2.7.9 |
| symfony/security-core | >= 2.4.0, < 2.6.13 |
2.6.13 |
| symfony/security-core | >= 2.7.0, < 2.7.9 |
2.7.9 |
| symfony/symfony | >= 2.3.0, < 2.3.37 |
2.3.37 |
| symfony/symfony | >= 2.4.0, < 2.6.13 |
2.6.13 |
| symfony/symfony | >= 2.7.0, < 2.7.9 |
2.7.9 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
symfony/security Packagist → 2.3.37
- composer
composer require symfony/security:^2.3.37
symfony/security-core Packagist → 2.6.13
- composer
composer require symfony/security-core:^2.6.13
symfony/symfony Packagist → 2.3.37
- composer
composer require symfony/symfony:^2.3.37
Severity breakdown
CVSS 3.0 7.5
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Weakness
CWE-332: Insufficient Entropy in PRNG
The lack of entropy available for, or used by, a Pseudo-Random Number Generator (PRNG) can be a stability and security threat.
How to prevent it
- Architecture and Design, Requirements: Use products or modules that conform to FIPS 140-2 [REF-267] to avoid obvious entropy problems. Consult FIPS 140-2 Annex C ("Approved Random Number Generators").
- Implementation: Consider a PRNG that re-seeds itself as needed from high-quality pseudo-random output, such as hardware devices.
- Architecture and Design: When deciding which PRNG to use, look at its sources of entropy. Depending on what your security needs are, you may need to use a random number generator that always uses strong random data -- i.e., a random number generator that attempts to be strong but will fail in a weak way or will always provide some middle ground of protection through techniques like re-seeding. Generally, something that always provides a predictable amount of strength is preferable.
References
Advisories
Other links
- github.com/symfony/symfony/pull/17359
- github.com/FriendsOfPHP/security-advisories/blob/master/symfony/security-core/C…
- github.com/FriendsOfPHP/security-advisories/blob/master/symfony/security/CVE-20…
- github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-201…
- symfony.com/cve-2016-1902
- landaire.net/blog/cve-2016-1902-symfony-securerandom
- symfony.com/blog/cve-2016-1902-securerandom-s-fallback-not-secure-when-openssl-f…
- debian.org/security/2016/dsa-3588
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-2v3c-qxhr-7vpv Symfony: Unbounded Recursion in the YAML Inline Lexer Lets a Single Document Crash the Process | High | Also affects symfony/symfony |
| GHSA-r925-mgvr-h9cc Symfony: ReDoS in HeaderUtils::split() Reachable Through the Cache-Control Request Header | High | Also affects symfony/symfony |
| GHSA-h5x3-xfc9-m39h Symfony: UrlGenerator Dot-Segment Encoding Skips Every Other Chained `../` or `./` → Generated URL Collapses Off-Route Under RFC 3986 Normalization | Medium | Also affects symfony/symfony |
| GHSA-v3wm-qf9p-c549 Symfony: HtmlSanitizer URL Parser Deny Gates Underinclusive: Percent-Encoded BiDi Marks and Unicode Whitespace Bypass Visual-Spoofing Defense | Medium | Also affects symfony/symfony |
| GHSA-rrj9-5q2j-4gvr Symfony: Mailomat Mailer Webhook Parser Reads the HMAC Algorithm from the Request: Signature Algorithm Downgrade | Medium | Also affects symfony/symfony |
| GHSA-38cx-cq6f-5755 Symfony: IpUtils::PRIVATE_SUBNETS Omits IPv6 Transition Forms (6to4, NAT64, Teredo, IPv4-compatible): SSRF Bypass in NoPrivateNetworkHttpClient | High | Also affects symfony/symfony |
| GHSA-6h46-9jf5-q59x Symfony: Security Firewall Bypass via failure_forward Subrequest: Unauthenticated Access to access_control-Protected GET Routes | High | Also affects symfony/symfony |
| GHSA-x5qj-865h-mgvm Symfony: HtmlSanitizer UrlAttributeSanitizer Misses URL Attributes | Medium | Also affects symfony/symfony |
MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.
Check your repos with MergeHarbor