CVE-2012-1577
📋 TL;DR
This vulnerability in OpenBSD's random number generator returns predictable values when seeded with zero, compromising cryptographic security. It affects systems using OpenBSD's libc random() function with improper seeding. Attackers can potentially predict random values used in security-sensitive operations.
💻 Affected Systems
- OpenBSD
- dietlibc
📦 What is this software?
Dietlibc by Dietlibc Project
Openbsd by Openbsd
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of cryptographic keys, session tokens, and security mechanisms relying on random number generation, leading to data breaches and system takeover.
Likely Case
Weakening of cryptographic operations, predictable session IDs or nonces, and potential bypass of security controls that depend on randomness.
If Mitigated
Limited impact if proper seeding practices are followed and random() isn't used for critical security functions.
🎯 Exploit Status
Exploitation requires understanding of application's random number usage and ability to influence seeding. Proof-of-concept code exists in security advisories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: OpenBSD: fixed in random.c revision 1.16 and later
Vendor Advisory: http://www.openwall.com/lists/oss-security/2012/03/23/14
Restart Required: Yes
Instructions:
1. Update OpenBSD to patched version. 2. Recompile affected applications. 3. Restart services using libc random functions.
🔧 Temporary Workarounds
Proper seeding workaround
allEnsure applications always seed random() with non-zero values using proper entropy sources
srand(time(NULL) ^ getpid());
srand((unsigned int)time(NULL) * getpid());
Use alternative RNG
allReplace random() calls with cryptographically secure alternatives like arc4random() or /dev/urandom
# Replace random() with arc4random() in source code
# Use read from /dev/urandom for cryptographic operations
🧯 If You Can't Patch
- Audit all applications for random() usage and ensure proper non-zero seeding
- Implement application-level monitoring for predictable random number patterns
🔍 How to Verify
Check if Vulnerable:
Test if random() returns predictable sequence when seeded with zero: compile test program that calls srand(0) and prints several random() valuesCheck Version:
uname -a (for OpenBSD), check libc version with ldd --versionVerify Fix Applied:
Verify OpenBSD version includes random.c revision 1.16 or later, or test that random() no longer returns predictable sequence when seeded with zero📡 Detection & Monitoring
Log Indicators:
- Unusual patterns in generated tokens or IDs
- Repeated cryptographic failures
Network Indicators:
- Predictable session IDs in network traffic
- Repeated nonce values in protocols
SIEM Query:
Search for applications calling srand(0) or predictable random number patterns in security logs🔗 References
- http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/lib/libc/stdlib/random.c#rev1.16
- http://www.openwall.com/lists/oss-security/2012/03/23/14
- https://github.com/ensc/dietlibc/blob/master/CHANGES
- https://security-tracker.debian.org/tracker/CVE-2012-1577
- http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/lib/libc/stdlib/random.c#rev1.16
- http://www.openwall.com/lists/oss-security/2012/03/23/14
- https://github.com/ensc/dietlibc/blob/master/CHANGES
- https://security-tracker.debian.org/tracker/CVE-2012-1577
