Does Hinek and Lam's Paper prove that Common Modulus Attacks is possible with non-coprime public exponents? We know that Common Modulus Attacks work with coprime public exponents $(e',s)$ such that $${e_1}s+{e_2}t=\gcd(e_1,e_2)=1$$
I am reading Hinek and Lam's Paper: Common Modulus Attacks on Small Private Exponent RSA and Some Fast Variants (in Practice). Got confused, it seems they proved that Common Modulus Attacks would work with non-coprime public exponents, with the condition of &quot;Small Private Exponent RSA&quot;.
Is my understanding correct? Is there some example for this?
The first common modulus attack is described by G. J. Simmons

1983 A ‘weak’ privacy protocol using the RSA crypto algorithm

and if there is a common modulus and the public exponents are relatively prime (i.e. $\gcd(e_1,e_2)=1$) then recovering the message is easy ( no factoring).
As pointed in section 5 of your linked article;

Howgrave-Graham and Seifert’s small private exponent attack on common modulus RSA [1] improves upon Guo’s attack in several ways. In particular, the attack can be mounted with only two instances of RSA (although it gets stronger with more), the problems associated with relatively prime quantities are not a concern and, most importantly, the attack (even with only two instances) is much stronger.

So your understanding is correct.